Forschungsprojekte

Customer letter about our further development of high-tech resists Medusa, Electra and Phoenix

We would like to inform you about the further development of our high-tech resists Medusa 84, Electra 94 and Phoenix 81.

6. December 2024/by uschirmer

Important information about deliveries between years 2024 / 2025

In order to align operational procedures with the needs of our customers, we have set a final order acceptance date: Order stop: 12/11/2024 and Delivery stop: 12/13/2024

15. October 2024/by uschirmer

50th Issue of the AR NEWS

Content: 1. Allresist at the EIPBN and MNE conferences 2024 / 2. Worldwide interest in Medusa 84 - AR-N 8400 SiH / 3. Daughter Ulrike Schirmer now appointed as Managing Director / 4. Our current environmental activities: Tree planting / 5. No price increases for listed products in 2025😊

15. October 2024/by uschirmer

October 2024: Worldwide interest in Medusa 84 – AR-N 8400 SiH

Allresist will soon offer ready-to-use resists as a replacement for HSQ in three different layer thicknesses: 50 nm (4,000 rpm, 4 % solids), 100 nm (4,000 rpm, 7 % solids), 400 nm (4,000 rpm, 23 % solids) → 1.0 µm / 800 rpm

15. October 2024/by uschirmer

July 2024: Medusa 84 AR-N 8400 SiH, the improved HSQ alternative, in market launch

Through a targeted synthesis which precisely separates the stable and sensitive molecular fraction of the HSQ polymer, and through complex cleaning procedures, it is possible to offer a significantly more stable resist.

18. July 2024/by msendel

49th Issue of the AR NEWS

Content:
1. Allresist at the “8th Thermal Probe Workshop“ of Heidelberg Instruments Nano AG
2. From PPA powder to liquid resist: Phoenix 81
3. Medusa 84 SiH – SX AR-N 8400: Market launch has begun
4. Our current environmental activities: another tree-planting event!

28. April 2024/by uschirmer

January 2024: Electra 92 established on the market – AR-PC 5092.02

At AMOLF, Electra 92 was applied to HSQ deposited on a 40 nm thick SiO2 layer of a silicon wafer. Due to its highly hydrophobic surface, HSQ is particularly challenging. A specially adapted version of Electra 92 was required for this task.

29. January 2024/by uschirmer

Strategy workshop: we will not be available for you on January 30, 2024!

We will not be available for you on Tuesday, January 30, 2024 because of our strategy workshop but we will immediately take care of all inquiries and orders from January 31, 2024 again.

18. January 2024/by uschirmer

Donation for completed customer surveys

Thank you very much for your participation in our customer survey. Your support is essential to us to improve our products and services! Therefore, we transferred 200 € to the Save the Children charity organisation.

20. December 2023/by uschirmer

Important information about deliveries between years

In order to align operational procedures with the needs of our customers, we have set a final order acceptance date: Order stop: 12/11/2023 and Delivery stop: 12/13/2023

15. November 2023/by uschirmer

48th Issue of the AR NEWS

Content:
1. Allresist on the MNE 2023 in Berlin
2. Medusa 84 SiH – SX AR-N 8400, another alternative to HSQ with better properties
3. Rubin project – waveguide materials for the NIR/VIS range
4. Successful introduction of the new Electra 92
5. Coloured and fluorescent resists for optical applications

16. October 2023/by uschirmer

October 2023: Medusa 84 SiH – SX AR-N 8400 another alternative to HSQ

In contrast to Medusa 82, the optical transparency of Medusa 84 SiH is significantly higher, since it is made of purely inorganic components. This transparency is important for a large group of customers who use such resists for optical applications.

6. October 2023/by msendel

April 2023: E-beam PMMA resist AR-P 672.045 – the workhorse for electron beam lithography

Due to the high sales volume, AR-P 672.045 is our internal "market leader". This resist is used by three major microchip manufacturers in France, Germany, and China. The consumption is thus steadily increasing, and meanwhile more than 300 liters of this resist are ordered annually.

24. April 2023/by uschirmer

47th Issue of the AR NEWS

Content:
1. On February 20, Allresist received an important IHK certificate for exemplary CO2 balance
in determining their carbon footprint on the path to climate neutrality
2. Allresist awarded as “Employer of the Future” on March 15
3. EOS 72: Our new, highly sensitive and alkali-resistant e-beam resist
4. New ZIM project – Photoresists for concave and convex surfaces
5. Allresist represented again at the EIPBN and MNE congresses

13. April 2023/by uschirmer

January 2023: Standard resist AR-P 3510 – 30 years on the world market

Right from the beginning, the idea of sustainability was firmly anchored in the philosophy of our young company. One of the first advanced developments of Allresist was the replacement of teratogenic solvents in the positive photoresist AR-P 351 with safer solvents. This is how the standard resist AR-P 3510 was created, in which the excellent lithographic properties of AR-P 351 were retained, but the resist was now significantly less dangerous to health for the user.

15. January 2023/by uschirmer

Strategy workshop – we will not be available for you on January 13th, 2023!

We have our strategy workshop today and are working as a team on how we can become even better for you! We will not be available but we will take care afterwards immediately on all inquiries and purchase orders.

Thank you for your understanding, Team Allresist

12. January 2023/by uschirmer

October 2022: Optimised Electra 92 – a new AR-PC 5092

We have now achieved a quality of aniline polymers that does not require the addition of isopropanol, which also increases the stability of AR-PC 5092 resist mixtures. Long-term tests demonstrated that the storage stability is significantly higher than with previous Electra variants.

19. October 2022/by uschirmer

46th Issue of the AR NEWS

Content:
1. 30 years of Allresist: Appreciation by Prime Minister Woidke
2. Allresist on the EIPBN in New Orleans
3. Further improved Electra 92 - new AR-PC 5092
4. Allresist on the MNE in Leuven
5. Rubin-project - waveguide materials for the NIR/VIS-range
6. Allresist determines its CO2 footprint

19. October 2022/by uschirmer

30 years Allresist

This anniversary is a special highlight for us, now looking back on 30 years of a very successful company history in which we have been able to implement our vision of an ecologically sustainable, but still economical resists production step by step.

26. August 2022/by uschirmer

Poly(phthalaldehyde)-based electron beam resists, University of Tübingen

A direct positive patterning of PPA layers is possible by electron bombardment. Similar to the irradiation of normally used e-beam resists like e.g. CSAR 62 or PMMA, the electron beam causes a fragmentation of the polymer chains.

27. July 2022/by

July 2022: Our resist triplet of the month – presented at the Triple-Beam (EIPBN 2022)

After the corona-related merely online possible presence in the past two years, Allresist finally again took part live at the EIPBN in New Orleans, and we experienced a high interest in our resists at our booth.

4. July 2022/by

Positive two- layer lift-off system

These systems have a bottom resist that is not photosensitive but soluble in alkali. The polymers must be composed in such a way that the lacquer coat withstands a coating with a photoresist with the solvent PMA (PGMEA) without any problems. Otherwise there would be a mixing of both resist layers.

14. June 2022/by

Electron beam resists

Among the first resists used (since about 1980) and still applied in many cases are short-chain (50.000 g/mol (50k)) as well as long-chain (950.000 g/mol (950k)) poly(methyl methacrylate) (PMMA resist, sensitivity at 100 keV approximately 250 – 500 µC/cm2).

13. June 2022/by

Electron beam lithography systems

Significant components of electron beam lithography systems are the electron source, the electro-optical system and the focusing system (deflection or respectively projection unit). Hot cathodes are used for equipment with lower resolution, devices with higher resolution, however, preferably need thermic field emission sources.

9. June 2022/by

Generation of secondary electrons

Alongside the occuring elastic scattering effects at a collision with other electrons or atoms, incoming primary electrons can also be scattered inelastically when entering or traversing resist layers.

9. June 2022/by

E-beam resist: Procedures

There are both mask-based and maskless writing procedures in electron beam lithography. More up-to-date systems use defined beams with, by the application of masks, selectively adjusted geometrical cross sections or respectively profiles, which are deflected upon the various positions (vector scan mode).

9. June 2022/by

Three-layer system CSAR/PMMAcoMA/PMMA

A further variant for the structure of three-layer systems uses 950k PMMA as bottom resist, AR-P 617 as middle layer and CSAR 62 as top resist. There is no mixing during the coating, thus ensuring a defined layer buildup. AR-P 617 can be coated on all PMMA’s (50k – 950k) without any problems, besides, the coating with AR-P 6200 (CSAR 62) is successful as well since anisole does not dissolve AR-P 617.

9. June 2022/by

T-gates with three-layer system CSAR/PMMAcoMA/PMMA

T-gate structures are often required for the fabrication of electronic components (MEMS, HEMTs). Corresponding nanostructures can be realized via e-beam lithography in multi-layer processes. Generally, resist layers with different sensitivities like e.g. PMMAs with varying molecular weight distributions are coated on top of each other, irradiated with electrons and then developed in one step.

8. June 2022/by

Basics

Information on:

Polymer resists (layer builders)
Photosensitive components
Cross linker
Other resist components (adhesion promoter, tenside, solvent, colorant)
Process information such as: Cleaning of substrates, adhesive strength, dilution of resists, yellow light, softbake, rehydration, exposure and storage
Process procedures such as: Lift-off procedures, wet-chemical etching, dry-chemical etching, UV-curing, lithographic procedures and stabilization/curing of resist layers

See Photo resists: General

8. June 2022/by

E-beam resists: General

Electron beam lithography is a special procedure for the structuring of electron beam sensitive resist layers in order to produce microelectronic circuits and photomasks used in photolithography.

8. June 2022/by

Scattering

If an electron beam with high energy is channeled onto a resist layer (5- 100 keV), forward scattering ( 90° in direction of arrival). The deflection causes the electron beam to widen, thus reducing resolution.

8. June 2022/by

Writing time

The minimum necessary exposure time for a certain area, at a given exposure dose, can be calculated by the following correlation: Area * dose = Duration of exposure * beam current.

8. June 2022/by

SCALPEL

A further mask-based technology is SCALPEL (Scattering with Angular Limitation Projection Electron-beam Lithography). Due to the interposed mask, certain parts of the electron beam are shadowed. The scattering layer strongly deflects incident electrons. A great advantage of this procedure as compared to electron absorption is less loading and less heating of the mask.

7. June 2022/by

Raster and vector scan principle

Raster scan principle is a procedure in which the electron beam is led line by line over the exposure area, comparable to the beam guidance in an electron microscope. The structures are exposed by switching the electron beam on and off while continuously moving the substrate (XY regulation).

7. June 2022/by

Proximity effect

A part of the high-energy electrons which impact on the substrate is stopped and cannot be conducted at all or only very slowly toward ground, especially in the case of insulating substrates such as quartz. The substrate and respectively the resist charges itself negatively and the electron beam is deflected uncontrollably from the desired position during exposure.

7. June 2022/by

Laser ablation of PPA (Phoenix 81)

PPA layers can also be structured by laser ablation. Substrates coated with AR-P 8100 were structured with pulsed laser light at different wavelengths at the IOM Leipzig (Dr. Klaus Zimmer). In this process, architectures with very little edge roughness could be generated. In the absorption range of PPA, at 248nm, complete ablation was achieved without damaging the silicon substrate.

7. June 2022/by

ATLAS 46 in general

The resists Atlas 46 S = AR-N 4600-10 and Atlas 46 R = AR-N 4650-10 are photoresists with negative effect and high layer thickness with extremely stable resist structures. In addition, AR-N 4650-10 is removable easily and thus very well suited for photolithographic and electro-plating applications. The characteristics of AR-N 4600-10 are comparable to those of SU-8.

7. June 2022/by

Black resist

For a surprisingly high number of applications, it is important to disable the transparency of the substrates completely, while still having the option to generate structures.

1. June 2022/by

General: Resist composition

The resists most widely used by far are the positive photo resists, followed by negative photo resists. However, there are other special resists as well.
Image reversal resists are positive resists with an additional amine. Depending on the manufacturing process, positive or negative images can be generated.

1. June 2022/by

Ready-to-use spray resists with EVG devices (positive and negative)

Spray coating is often used for the coating of complex topologies. There are various manufacturers of spray coating equipment, probably the best known are EV Group and Süss Microtec. Both producers use different strategies and devices for spraying, and therefore ready-to-use spray resists must be adjusted for the particular equipment.

31. May 2022/by

Thermally stable two-layer lift-off systems

The Resist Wiki article "Positive two-layer lift-off systems" describes the principle of these two-layer systems. During the application of lift-off structures, temperatures above 150 °C occur frequently, for example during sputtering. If the usual photo resists are used as top layer, the lift-off structure melts and thus becomes useless for the process.

25. May 2022/by

Dilution of resists

Almost all photo resists contain PMA (PGMEA) as a solvent. This solvent is therefore the most common thinner and offered by us as AR 300-12 angeboten. The PMA is often used for the removal of edge beads.

25. May 2022/by

Adhesive strength

Adhesive agents serve to improve adhesion, e.g. the adhesion promoter AR 300-80, which is applied by spin coating as thin layer of approximately 15 nm immediately before the resist coating. It is also possible to evaporate HMDS on the substrate, in this process, the monomolecular coat on the wafer surface improves adhesion, because it becomes hydrophobic and better attaches to the resist.

24. May 2022/by

One-layer and two-layer lift-off

Lift-off structures are needed for many technologies. There are one-layer and two-layer processes. For one-layer, only one resist is used. Typical examples are negative resists, see Resist-Wiki "Generation of undercut structures with negative resists". However, there are also positive resists (AR-P 5300) for the lift-off. There is only a slight difference, though in most cases, which, however, is sufficient for many procedures.

24. May 2022/by

CSAR 62 – Mechanism of action

By comparison with PMMA resists, CSAR 62 is characterized by a higher sensitivity and a significantly better plasma etch resistance. The main components of the resist are poly(α-methylstyrene-co-chloromethacrylic acid methyl ester), an acid generator and the safer solvent anisole. The higher sensitivity results from the addition of halogen atoms to the polymer chain.

24. May 2022/by

Solution

In contrast to photolithography, the solution of e-beam lithography is practically unlimited by wavelength. Electrons of an energy of 25keV have a wave length of < 0,01 nm. The maximum resolution thus is crucially determined by the beam diameter.

23. May 2022/by

Loading

A part of the high-energy electrons which impact on the substrate is stopped and cannot be conducted at all or only very slowly toward ground, especially in the case of insulating substrates such as quartz. The substrate and respectively the resist charges itself negatively and the electron beam is deflected uncontrollably from the desired position during exposure.

23. May 2022/by

New solvent remover

A new strong solvent remover is able to solve resist layers tempered at room temperature. It is remarkable that the remover takes the same effect on novolak based as well as PMMA based resists and thus is suited for versatile applications. It must be pointed out, however, that the flash point of the remover is below 21 °C and therefore needs to be handled with care.

19. May 2022/by

Waterfree developable special resist SX AR-N 4810/1

The new special resist SX AR-N 4810/1 is a chemically enhanced photo resist based on PMMA, which can be developed waterfree – crucial in the case of moisture-sensitive substrates – with organic solvents.

19. May 2022/by

Top surface imaging (TSI) photoresist – principles

Roland and Coopmans intensively studied the fundamentals of the top surface imaging technology which is based on a selective resist silylation process (DESIRE process). A positive photoresist specifically optimised for this purpose with considerably increased content of light-sensitive components (LSCs) is exposed image-wise.

19. May 2022/by

Positive resist for temperature sensitive substrates

In many cases, substrates meant to be structured may not be heated above 50 – 70 °C. These can be glass partitions which distort at higher temperatures and thus might lose their size accuracy. However, some organic polymers which are to be coated are temperature sensitive. Moreover, thermosensitive structures may already exist on the substrates.

12. May 2022/by

Chemically enhanced negative resist without cross-linking

In some applications, the substrate on which the negative resist is to be applied cannot be heated. This may be the case for sensitive glass and especially for very big substrates.

11. May 2022/by

Process conditions

Air bubbles often occur when resist bottles are e.g. shaken or moved around before coating, or if a resist is diluted. They may also appear if the coating step is performed immediately after opening of the resist bottle, particularly if the resist temperature is not allowed to adjust to room conditions.

11. May 2022/by

Aqueous-alkaline removers

The simplest but nevertheless highly effective removers are sodium hydroxide (NaOH) and potassium hydroxide (KOH) solutions. Already a 4 % KOH solution will remove basically all novolac-based photo- and e-beam resists within a few seconds.

25. April 2022/by

45th Issue of the AR NEWS

Content:
1. Ukraine at war: We also bear responsibility
2. COVID-19: An endless story?
3. Allresist again present at congresses
4. Eco-friendly "green" PMMA developer
5. Profit project of the State of Brandenburg QD-LED
6. Allresist has planted trees

21. April 2022/by AllAdmin

Types of developers

There are two main groups of developers: solvent-based and aqueous-alkaline developers. The solvent-based ones are intended mainly for PMMA e-beam resists, for CSAR 62 and also for special polymer based products. In this process, solvents such as methylisobutylketone (MIBK), IPA (partly with water) for PMMA, amyl acetate, MIBK, DEK, DEM, xylol for CSAR 62 and ethylbenzene as well as hexane are used for the protective coating.

14. April 2022/by

Solvents and workplace safety

All resists we offer as well as a large number of process chemicals contain organic solvents. When handling these products, provisions of the Ordinance on Hazardous Substances are to be complied with. The safety data sheets of our products are intended to provide required data and handling recommendations for the user to take effective measures for health protection, workplace safety and environmental protection.

14. April 2022/by

Solvent removers

The classical remover is acetone which is, together with isopropanol, used as cleaning agent in probably every lab worldwide. The dissolving power of acetone for non- or only low-baked films (up to 120 °C) is excellent.

14. April 2022/by

April 2022: New environmentally friendly developer for PMMA resists AR 600-57

Exceptionally we present a new PMMA developer in the "Resist of the month" section today, because its potential possibilities will probably also inspire our users. This developer is a mixture of isopropanol and water – which may sound surprising at first, since both components individually do not attack PMMA layers.

4. April 2022/by

Protective coating as spray resist for the smoothing of surfaces

PMMA layers (novolak layers) feature an extremely smooth surface. A surface roughness of less than 2nm was measured on resists which were thus optimized. This characteristic can be used for the smoothing of glass surfaces, for instance.

22. March 2022/by

PPA for two layer applications

Report on the two layer system, respectively lift-off: AR P-617 (250nm) with PPA (30nm), development followed by vapor coating of Al (40nm).

22. March 2022/by

AR-P 617 Two layer lift-off system

An alternative version of the structure of two layer systems emanates from only one resist: AR-P 617 (PMMAcoMA 33). At increasing temperature, AR-P 617.08 becomes linearly more sensitive.

22. March 2022/by

PMMA e-beam resist, positive and negative in the case of overexposure, suitable for bridge structures

PMMA resists work positively under standard conditions. The long polymer chains are broken into small fragments by the irradiation process. PMMA 950k with a molar mass of 950 000 g/mol is primarily reduced to a molar mass of about 5000 g/mol. These short-chain polymers are readily soluble in the developer, which is not the case for the polymer with the initial high molar mass.

21. March 2022/by

PMMA e-beam resist with flat gradation for three-dimensional structures

It is advantageous for the fabrication of three-dimensional structures if the gradation (contrast) is low. A resist with very high contrast will always generate perpendicular resist flanks. Smallest changes of the dose induce a rapid shift from undeveloped to the completely developed state. If the gradation is low, the dose difference between the undeveloped and the completely developed state is accordingly high.

21. March 2022/by

Temperature resistance of e-beam polymers

Layers and structures of e-beam polymers possess different temperature resistance properties. PMMA layers are generally the most stable.

15. March 2022/by

CSAR 62 nanostructures written at 100 kV

Applying an acceleration voltage of 100 kV has the advantage that the proximity effect due to electron backscattering can be avoided.

14. March 2022/by

Allresist supports Ukraine

We strongly condemn Putin's brutal war of aggression. He brings untold suffering to the people of Ukraine.

7. March 2022/by

High-resolution negative e-beam resist AR-N 7520.17new for etching application

Very even and smooth 300nm ridges could be achieved with AR- 7520.17new and a coating thickness of 400nm.

2. March 2022/by

Order of Merit of the State of Brandenburg for Brigitte and Matthias Schirmer

On January 28, 2022, Brigitte and Matthias Schirmer were awarded the Order of Merit of the State of Brandenburg by Prime Minister Dietmar Woidke. This extraordinarily high award for special achievement recognizes their work and in particular their commitment to sustainability. From the very beginning, it was of particular importance for the Schirmer couple to implement not only economic success, but with equal importance social and ecological aspects in their newly founded company Allresist.

2. February 2022/by uschirmer

January 2022: Versatile Phoenix 81 (AR-P 8100)

Phoenix 81 was developed as part of a Eurostar project in cooperation with Swisslitho AG (now Heidelberg Instruments Nano). Using a NanoFrazor and thermal scanning probe lithography (t-SPL), structures as small as 10 nm can be written by dipping a hot needle into the resist layer and evaporating the resist at the tip (see also AR NEWS, 42nd issue).

13. January 2022/by uschirmer

Negative poly(hydroxystyrene) and (hydroxystyrene-co-MMA) photoresist with high-temperature stability

As an alternative to the polyimide negative resist, SX AR-N 4340/6 was developed, a highly sensitive CAR negative resist based on polyhydroxystyrene, which can be developed under aqueous-alkaline conditions.

13. January 2022/by

44th Issue of the AR NEWS

Content:
1. Working in the times of Corona
2. More efficient manufacture of Electra 92
3. RUBIN – highly promising project in optical sensor technology
4. EOS 72, a chemically amplified positive e-beam resist
5. Contribution against climate changes: Allresist plants trees

14. October 2021/by uschirmer

October 2021: More efficient production of Electra 92

Many companies meanwhile use the conductivity of Electra layers for their processes and technologies. Since its introduction on the market in 2018, synthesis and processing of Electra have continuously been improved. The conductivity of this resist could for example be increased by a factor of five between 2018 and 2020.

1. October 2021/by uschirmer

July 2021: CAR 44 for galvanic molding

The successful evaluation of our development at one of our largest customers was the reason for us to select AR-N 4400-50 as resist of the month of July.

6. July 2021/by

43rd Issue of the AR NEWS

Content:
1. Allresist with view to the future
2. Investing in novel technologies
3. Structurable conductive layers
4. CSAR 62 – great demand around the world

9. April 2021/by

April 2021: CSAR 62 – In demand around the world

Resist CSAR 62 is meanwhile established worldwide, with continuously increasing demands. Since we manufacture the polymer by ourselves, we had to scale up polymer synthesis. First of all, CSAR 62 made the jump from laboratory scale to a 20-liter trailer.

30. March 2021/by

January 2021: Optimised process for negative photoresist Atlas 46

We continued the development work on our new Atlas 46 photoresist also in 2021. Due to own results or recommendations and requests from our users, its formulation and properties were now improved.

20. January 2021/by uschirmer

42nd Issue of the AR NEWS

Content:
1. Prime Minister Dietmar Woidke visits Allresist in times of Covid-19
2. Higher shelf live and more sensitive HSQ-alternative Medusa 82 for grayscale
lithography
3. Medusa for UV lithography
4. Thermally structurable resists

9. October 2020/by

July 2020: Bottom resist AR-BR 5400, the “workhorse” for two-layer processes

In 2004, the first bottom resist (BR) was developed in collaboration with the Center for Intelligent Systems (CiS, Erfurt). This bottom resist is non-light sensitive and can be developed in an aqueous alkaline manner.

28. July 2020/by AllAdmin

Forays through the lithography of microelectronics (Matthias Schirmer)

Due to the fast-paced development of photolithography since the 1990s, only a short summary of the different techniques and applications can be given here. For in-depth information on the multitude of facts, technologies and procedures presented in each chapter, the added references should be consulted.

20. May 2020/by AllAdmin

Customer information Corona virus

The novel corona virus (COVID-19) is spreading rapidly across national borders. So far, the operational processes of Allresist GmbH have hardly been affected. We strive to meet our customers' requirements as best we can in this tense situation and to minimize the impact on our operational processes as much as possible. The focus is on protecting our colleagues and our customers.

15. May 2020/by AllAdmin

41st issue of the AR NEWS

Content:
1. 27 years of Allresist – firmly established on the world market
2. Allresist successful on the congresses Triple Beam (EIPBN 2019) and MNE 2019
3. Medusa 82 for e-beam graytone lithography
4. Resist structures for the spin Hall effect

9. April 2020/by

January 2020: Black resist SX AR-N 8355/7

Optically dense resists play an increasingly important role in industry. So-called black resists are required in optical industry, in automotive industry (for headlights) and in the manufacture of rotary encoders.

25. February 2020/by AllAdmin

Oktober 2019: Medusa 82 UV

Medusa 82 UV was already chosen as resist of the month in January 2019. Back then, we highly appreciated the first results for a use as photoresist. Shown are now results with respect to an application in grayscale lithography which were also presented at the MNE 2019 in Greece.

22. October 2019/by AllAdmin

40th issue of the AR NEWS

Content:
1. 27 years of Allresist – firmly established on the world market
2. Allresist successful on the congresses Triple Beam (EIPBN 2019) and MNE 2019
3. Medusa 82 for e-beam graytone lithography
4. Resist structures for the spin Hall effect

22. October 2019/by AllAdmin

Förderung unternehmensWert:Mensch

4. October 2019/by AllAdmin

Allresist presents Medusa 82 at the MNE 2019 in Rhodes

Just as in the previous years, Allresist was represented at the MNE congress with a prestigious booth. This year’s MNE was guided by the motto "Going Nano in Homer's Land" – an excellent connecting point for our presentation since our new e-beam resist is named Medusa 82.

30. September 2019/by AllAdmin

Produktentwicklungen

10. May 2019/by AllAdmin

Extension of the production facilities

On April 29, 2019, Allresist put the new production wing into operation in which from now on 1,000 l resist batch productions and large-scale syntheses will take place with state-of-the-art technology and taking into account all safety considerations.

29. April 2019/by AllAdmin

April 2019: Phoenix 81

Allresist developed Phoenix 81 (AR-P 8100) within the scope of a Eurostars project together with SwissLitho AG and other partners. SwissLitho recently added a laser direct writer to the NanoFrazor device (see Fig. 1)

22. April 2019/by AllAdmin

39th Issue of the AR NEWS

Content:
1. Synthesis week in the new production tract
2. Allresist at the congresses Triple Beam (EIPBN 2019) and MNE 2019
3. Medusa 82 passed comprehensive application tests
3.1. Dissolution test with the sensitive PAG-Medusa 82 (SX AR-N 8250)
3.2. Influence of a PEB on the sensitivity of Medusa 82
3.3. Plasma etching tests with Medusa structures
3.4. Medusa 82 with specifically low contrast
4. Five coloured negative resists on one glass wafer

22. April 2019/by AllAdmin

38th Issue of the AR NEWS

Content:
1. 26 years of Allresist - Inauguration of the new plant on the company anniversary
2. Allresist’s great success with Medusa 82 at the MNE 2018
3. Further Allresist highlights at the MNE
4. Atlas 46 and CAR 44 for e-beam lithography
5. Phoenix 81 – World-wide sales begin!
6. Offspring at Allresist – The next generation!

22. October 2018/by AllAdmin

Resist of the Month of October: Medusa 82 – alternative to HSQ

Allresist now developed Medusa 82 as an alternative to HSQ resists. Due to a modification of the polymer, resist Medusa 82 can be handled very easily.

21. October 2018/by AllAdmin

Einweihung des neuen 450 m² großen Anbaues zum 26. Firmenjubiläum

Unser zweiter Anbau wurde dringend erforderlich, weil Allresist seit Jahren auf stetigem Wachstumskurs ist. Besonders die Hightech Produkte CSAR 62, Electra 92 und Atlas 46 made in Strausberg erfreuen sich großer Beliebtheit bei den Kunden im In- und Ausland.

16. October 2018/by AllAdmin

CAR 44 for e-beam lithography

We now succeeded in finding a remarkable solution for high-layer e-beam structuring. The negative resist CAR 44 (AR-N 4400-10) was coated to yield a layer with a height of 9.5 μm, dried, and irradiated.

12. October 2018/by AllAdmin

Atlas 46 for e-beam lithography

A new application field for Atlas 46 is electron beam lithography, as experiments with a thin Atlas resist layer patterned by e-beam lithography demonstrated. At a layer thickness of 450 nm, 200 nm lines were written into this layer. The sensitivity was 70 μC/cm² at an acceleration voltage of 100 kV.

12. October 2018/by AllAdmin

Medusa 82 for EUV applications

For an optimum handling of EUV lithography using the RWTH system, a sensitivity range of 30-40 mJ/cm² is desired. A Medusa 82 sample supplemented with 2.5 % photoacid generator (PAG) already reached this target range. These investigations will be continued within the scope of a research project.

12. October 2018/by AllAdmin

Medusa 82: Influence of post exposure bake (PEB)

The addition of photoacid generators (PAGs) can significantly increase the sensitivity of Medusa 82 (see Resist Wiki “Medusa with photoacid generator”). Another option is to add a PEB after e-beam exposure. Even if substrates were previously stored for several days, the sensitivity significantly increases depending on the temperature and the duration of the PEB.

12. October 2018/by AllAdmin

Medusa 82 with photoacid generator (PAG)

One disadvantage of HSQ and Medusa 82 is the comparably low sensitivity, which can however be increased by an addition of photoacid generators.

12. October 2018/by AllAdmin

Great success with Medusa 82 at the MNE

Once again Allresist participated in the MNE with a large, attractive booth and new innovations. As in past years, the interest of the conference participants in our diverse new developments was great. The absolute highlight however was the introduction of our Medusa 82, an excellent alternative to HSQ resists.

28. September 2018/by AllAdmin

Structuring by ablation of the resist materials

The basic principle of laser ablation is that laser irradiation of a certain wavelength introduces so much energy into the resist material which is modified for ablation that the resist polymer is destroyed and then vaporizes as low molecular weight fragments.

9. July 2018/by AllAdmin

Phoenix 81 – Storage conditions and dispatch

In the final stage of the Eurostar PPA-Litho project which was aimed to develop the resist Phoenix, we achieved to generate far more stable PPA polymers by optimizing the synthesis procedure. Pure polyphthalaldehydes which were subjected to a “stress test” for 14 days at 37 °C showed no decomposition. These resists can thus be shipped without cooling; this however only applies to pure PPA polymers.

9. July 2018/by AllAdmin

Medusa 82 – the alternative to HSQ-resists, storage stability

Our research team successfully developed a negative resist with high resolution and plasma etching stability in oxygen: Medusa 82. Already with the first samples, it was possible to achieve the properties of HSQ.

9. July 2018/by AllAdmin

Black-Protect – stable protective coating for HF and KOH etchings

Allresist offers the protective coating SX AR-PC 5000/40 for HF and KOH etchings already for a few years. Layers of 5 μm are able to withstand a 48 % hydrofluoric acidic solution for several hours. Also 40 % KOH solutions for silicon etchings do not attack the layer.

9. July 2018/by AllAdmin

Bleachable resists

The basic idea behind dyed resists developed within the scope of the Photoenco project (June 2016 - May 2019) was that dyes are mixed into the polymer matrix of the resist which then either change their colour or become colourless upon irradiation.

9. July 2018/by AllAdmin

Resist of the Month July: Medusa 82 – the alternative to HSQ-resists

Our research team successfully developed a negative resist with high resolution and plasma etching stability in oxygen. Already with the first samples, it was possible to achieve the properties of HSQ.

3. July 2018/by AllAdmin

Allresist at the EIPBN 2018 Conference in Puerto Rico

Allresist attended the “triple-beam” conference EIPBN 2018 for the first time. Matthias Schirmer and Dr. Christian Kaiser answered many inquiries at the exhibition stand, especially questions regarding electron beam resists.

6. June 2018/by AllAdmin

2L-Lift-off system AR-P 617 – AR-P 8100

Anisole PPA solutions can be coated on PMMAcoMA 33 (AR-P 617). The single layers add up in this case; no mixing of layers occurs, which is a decisive prerequisite to realise defined 2- or also 3-layer systems.

25. April 2018/by AllAdmin

CSAR 62 single layer lift-off system

With our new development e-beam resist AR-P 6200 (CSAR 62), very fine structures like e.g. 10 nm wide trenches can be manufactured with very high contrast (> 14) and comparably high sensitivity.

25. April 2018/by AllAdmin

Fluorescent resist structures with photoresists

Photoresists can also be used to incorporate fluorescent dyes. Particularly negative-tone photoresists are of interest in this regard, since the use of selected fluorescent dyes allows defining an adjustable emission in variable wavelength ranges. Resist layers with violet, blue, yellow, orange, or red fluorescence were produced by embedding the respective dyes into the negative-working Atlas 46 S resist.

25. April 2018/by AllAdmin

37th issue of the AR NEWS

Content:

1. Our building extension is progressing
2. Allresist at the congresses Triple Beam (EIPBN 2018) and MNE 2018
3. Atlas 46 variants for a selective two-layer build-up
4. Fluorescent resists for optics and sensors with Atlas 46 S
5. Medusa 82 – a resist turning into "stone" structures
6. New protective coating for KOH/HF etchings – BlackProtect SX AR-PC 5000/41

22. April 2018/by AllAdmin

Resist of the month of April: Fluorescent negative photoresist Atlas 46 S

These poly(phthalaldehydes) are also suitable for electron beam lithography and for the fabrication of 200 nm thick fibers (electrospinning). The material produced from these threads evaporates immediately upon heating, which offers interesting application possibilities.

6. April 2018/by AllAdmin

SX AR-PC 5060 F-Protect (replacement for Cytop)

The new, highly insulating protective coating SX AR-PC 5060 F-Protect represents a good alternative to the well-known resist Cytop®.

15. January 2018/by AllAdmin

Atlas 46 for nanoimprint lithography

The new development Atlas 46 could also be successfully used for nanoimprinting (University of Wuppertal, working group of Prof. Scheer). In a first step, nanostructures were produced with the negative-working resist

15. January 2018/by AllAdmin

Resist of the month January: SU 8 alternative – negative photoresist Atlas 46

The outstanding properties of SU-8 are well known to all users of microsystem technologies. Allresists new negative resist Atlas 46 S (solid) can easily be processed with high reproducibility of all properties and with high restistance of resist structures to all commonly used solvents. Atlas 46 S is thus perfectly suitable for all applications in which the layer is intended to remain permanently and resistively on the substrate.

2. January 2018/by AllAdmin

Zeitungsartikel zu 25 Jahren Allresist

Das 25-jährige Bestehen feierte das Team der Allresist GmbH im Rahmen einer großen Feierlichkeit. Zu diesem Anlass haben die regionalen Zeitungen ausführliche Berichte über das erfolgreiche Unternehmen veröffentlicht.

14. November 2017/by AllAdmin

36th Issue of the AR NEWS

Content:
1. 25 years of Allresist – a success story also of resist development
2. Allresist at the MNE Conference with Atlas 46
3. New innovative product developments
3.1. Fluorescent and coloured resists for optics and sensor technologies
3.2. Thick(er) CSAR 62 for the production of deep etch pits
3.3. CSAR 62 in three-layer systems for the generation of T-gates

22. October 2017/by AllAdmin

25 years of Allresist – A reason to celebrate!

In the quarter century of its existence, the Allresist Company established a solid place on the world market and an excellent reputation among its customers. We thus appropriately celebrated our company anniversary on 16 October 2017 with a festive event!

16. October 2017/by AllAdmin

CSAR 62 for thick films

Layers with a thickness of 1.5 μm were produced using AR-P 6200.18, thick. As shown by investigations at the KIT (IMT, Dr. Lothar Hahn), allows this layer thickness to generate very regular trenches with a width of 300 nm at a period of 300 nm (see Fig. 1).

11. October 2017/by AllAdmin

Fluorescent resist structures

Fluorescence is the spontaneous emission of light briefly after a substance is excited by electronic transitions. The emitted light has usually less energy than the previously absorbed light.

11. October 2017/by AllAdmin

Coloured negative photoresists

Allresist now also offers colored negative resists with the designation SX AR-N 8500. The difference to FUJIFILM resists is that only dyes and no pigments are dissolved in the resists. This allows to achieve a high resolution and high edge sharpness.

11. October 2017/by AllAdmin

Innovative new development at the MNE 2017

Allresist participated in the conference as a “silver sponsor” with an own large stand and presented many remarkable new developments. A particular highlight was our scientific poster on our new development AR-N 4600 (now Atlas 46) and the lecture by Dr. Gerngroß about this interesting negative photoresist.

28. September 2017/by AllAdmin

35th special issue of the AR NEWS

Content:
1. Allresist is planning a new building extension again in the 25th year of its existence
2. New innovative product developments
3. Scientific partnerships for the MNE 2017

21. September 2017/by AllAdmin

Resist of the month of October: Fluorescent resist structures with SX AR-P 672.08

Fluorescent structures are needed for optical components and in microscopy. In close collaboration with Precision Optics Gera GmbH we now achieved to add fluorescent dyes to PMMA e-beam resists on anisole basis which subsequently could be structured by electron beam lithography.

18. September 2017/by AllAdmin

Development cascade

The use of a cascade is recommended for optimum performance of the developer and for the highest cleanliness during immersion development. The development often takes place in only one container.

11. July 2017/by AllAdmin

CAR 44 on copper

If negative photoresist CAR 44 (AR-N 4400) is directly used on copper or copper-containing substrates, the following points must be observed.

11. July 2017/by AllAdmin

New AR 300-80 and contact angle measurement

In addition to the established adhesion promoter AR 300-80 (which is based on diphenylsilanediol), also other silicone-containing compounds may be used to render hydrophilic surfaces more hydrophobic.

11. July 2017/by AllAdmin

Allresist auf der MNE und Semicon

Allresist ist während des Jahres auch auf Messen und Kongressen vertreten.

Nutzen Sie die Chance und besuchen Sie uns!

MNE 2017 in Braga, Portugal (18. – 21. September 2017)

Semicon Europa 2017 in München (14. – 17. November 2017)

10. May 2017/by AllAdmin

34th issue of the AR NEWS

Content:
1. Allresist plans another building extension the in the 25th year of its existence
2. New sales partners
3. Thermally developable positive resist “Phoenix 81“
4. Negative photoresist “Atlas 46“– our effective alternative to SU-8
5. Positive CAR e-beam resist “EOS 72“– our response to FEP 171
6. 25 years of Allresist

21. April 2017/by AllAdmin

Allresists neue Produktentwicklungen in den Startlöchern

In unserem 25. Jubiläumsjahr entwickelt unsere FuE-Abteilung drei weitere brandneue für unsere Kunden interessante Produkte: Thermoentwickelbarer Positivresist „Phoenix 81“, „Atlas 46“ eine SU-8-Alternative, Positiv CAR-E-Beamresist „EOS 72“.

15. April 2017/by AllAdmin

4. April 2017/by AllAdmin

Brandenburger Innovationsfachkräfte

Entwicklung von direkt strukturierbaren Resists für Encoder-Scheiben

4. April 2017/by AllAdmin

E-Beam Resist

3. April 2017/by AllAdmin

Resist-Wiki

3. April 2017/by AllAdmin

Resist of the month April – Thermally developable positive resist Phoenix 81

These poly(phthalaldehydes) are also suitable for electron beam lithography and for the fabrication of 200 nm thick fibers (electrospinning). The material produced from these threads evaporates immediately upon heating, which offers interesting application possibilities.

3. April 2017/by AllAdmin

Eurostar-Projekt: PPA-Litho

Entwicklung von direkt strukturierbaren Resists für Encoder-Scheiben

31. March 2017/by AllAdmin

Eurostar-Projekt: PPA-Litho

Entwicklung und Produktion von thermisch strukturierbaren Resists

31. March 2017/by AllAdmin

Allresist now offers many solvents in lightweight HDPE bottles

Many solvents and process chemicals will become "lighter" in the future. Allresist now offers these products in HDPE instead of glass bottles.

17. February 2017/by AllAdmin

Top Surface Imaging E-Beamresist

The DESIRE process can also be used for electron beam lithography even though certain differences exist between photo and e-beam lithography. Structures are written into the resist layer by means of electrons.

3. February 2017/by AllAdmin

Fabrication of vertical flanks with CAR 44

AR-N 4400-50 was investigated at the TU Braunschweig with particular regard to the fabrication of well-defined resist architectures with vertical flanks.

20. January 2017/by AllAdmin

Use of PPA in multilayer processes

Anisolic PPA solutions can be coated onto PMMA (600k, 950k), PMMAcoMA (AR-P 617) as well as on bottom resist AR-BR 5480 (alternative to PMGI). The single layers add up in each case, and virtually no mixing takes place. It is thus possible to realize well-defined two- and three-layer systems by these means.

20. January 2017/by AllAdmin

Resist of the month January 2017: Optimised negative spray resist AR-N 2200

Spray resist AR-N 2220 is the only ready-to-use negative resist worldwide. This eliminates the need for the time-consuming and inaccurate mixing of a resist with solvents.

2. January 2017/by AllAdmin

33rd issue of the AR NEWS

Content:
1. 24th anniversary of Allresist
2. Allresist as silver sponsor at MNE 2016 in Vienna
3. News about CSAR 62 and Electra 92
4. Optimised T-gate structures with three-layer system of PMMA, copolymer 617, and CSAR 62
5. New developers for PMMAcoMA (AR-P 617, 50 kV)
6. New lab and new rotary evaporator for production

16. October 2016/by AllAdmin

Protective coating to prevent mechanical damage

Sensitive substrates can be protected against damage during handling with resist SX AR-PC 5000/3.1, which is especially important in the case of double-sided procedures.

4. October 2016/by AllAdmin

Resist of the month October 2016: Optimised T-gate structures with three-layer system PMMA, copolymer 617 and CSAR 62

T-gates are required for the manufacture of high-quality transistors. Allresist optimised several three-layer systems for this particular application and designed both universal developers for a single development step, as well as individual developers which are suitable to develop each one of the three layers specifically.

1. October 2016/by AllAdmin

Manufacture of undercut structures for T-gates in three-layer processes

In principle, several options exist to develop three-layer systems for the manufacture of T-gates. It is however crucial in each case that the different resists do not mix during the coating in order to ensure a coherent and well-defined layer build-up. AR-P 617 can be coated onto all PMMAs (50k - 950k) without any problems, since the resist solvent does not attack PMMAs. Vice versa can AR-P 617 also be coated with PMMA solutions in ethyl lactate or also anisole.

29. September 2016/by AllAdmin

Additional new experimental developers for AR-P 617

For some applications are universal developers of advantage, i.e. developers which are simultaneously well suited for a variety of resist families. Multilayer systems can in this case be developed in one step, and no change of the developer in between is required.

29. September 2016/by AllAdmin

New developers for PMMAcoMA (AR-P 617, 50 kV)

X AR 600-50/2 is a new, very sensitive and highly selective developer for AR-P 617. The dark erosion is very low even at longer development times. Layers of PMMA or CSAR 62 are not attacked, which is especially important for multi-layer processes.

29. September 2016/by AllAdmin

Evaluation of various developers for e-beam exposed CSAR 62 layers (100 kV)

To evaluate the suitability of various developers for CSAR 62, Dr. Lothar Hahn (Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology) kindly provided various substrates which had previously been exposed to 100 kV e-beam irradiation (dose variations).

29. September 2016/by AllAdmin

Surface imaging resist system SX AR-N 7100 – silylable photoresist

The negative photoresist experimental sample SX AR-N 7100 is a surface imaging and dry developable system. With this system, structures can be transferred into thick resist layers by means of plasma etching.

4. July 2016/by AllAdmin

Use of CSAR 62 for the manufacture of nanostructures on GaAs substrates

CSAR 62 is routinely used to produce innovative quantum devices at the TU Delft (Mr. Toivo Hensgens, TU-Delft, the Netherlands). For the structures shown below, a 72 nm layer of CSAR 62 was exposed to 100 kV and then developed with amyl acetate.

4. July 2016/by AllAdmin

Evaluation of various developers for e-beam exposed CSAR 62 layers (100 kV)

To evaluate the suitability of various developers for CSAR 62, Dr. Lothar Hahn (Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology) kindly provided various substrates which had previously been exposed to 100 kV e-beam irradiation (dose variations).

4. July 2016/by AllAdmin

Interference lithography

Interference lithography is a less frequently used method for patterning. The basic principle is the same as in interferometry or also in holography.

4. July 2016/by AllAdmin

Resist of the month July 2016: Negative PMMA resist for photolithography

Sensitive substrates do not tolerate aqueous-alkaline developers. For such cases, X AR-N 4800/16 was developed already several years ago. While this resist met all the demands placed on it, only a layer build up to 70 % with moderate sensitivity was possible.

1. July 2016/by AllAdmin

32nd issue of the AR NEWS

Content:
1. Allresist in the 24th year: A steady upswing with innovations
2. Electra 92 as conductive layer for SEM-imaging
3. Poly(phthalaldehyde) (PPA) as e-beam resist
4. Conductive polymer electrodes for stack actuators – smart3
5. Polyphotonics – new resists for optical components and applications in microelectronics

21. April 2016/by AllAdmin

Highly sensitive e-beam resist AR-P 617 (PMMA-copolymer)

The copolymer composed of methyl methacrylate and methacrylic acid is, in contrast to the pure PMMAs, able to form a 6-membered ring during thermal loading.

13. April 2016/by AllAdmin

CSAR 62 for EUV applications

In addition to the use in e-beam lithography, the highly sensitive e-beam resist CSAR 62 can also be structured by exposure to UV radiation since the resist strongly absorbs UV radiation in the wavelength range of 190 – 240 nm.

13. April 2016/by AllAdmin

HF etching of GaAs with CSAR 62 masks

Mr. Y. Nori from Lancaster University (Department of Physics, UK) could very successful generate structures for the production of photonic crystals with CSAR 62.

13. April 2016/by AllAdmin

BOE etching of SiO2 with CSAR 62 mask

Even the highly sensitive e-beam resist CSAR 62 can be used as mask for an etching process with HF (BOE, 10:1).

13. April 2016/by AllAdmin

New developers for AR-P 617

Our highly sensitive e-beam resist AR-P 617 is frequently used in two-layer processes, mostly in combination with PMMA, for the production of lift-off architectures like e.g. T-gates.

13. April 2016/by AllAdmin

Utilising Electra 92 for SEM applications

The coating with Electra 92 on highly electrically insulating polymers or also on glass allowed a high-quality imaging of nanostructures in SEM.

13. April 2016/by AllAdmin

Brandenburgs Wirtschaftsminister Albrecht Gerber bei Allresist zu Besuch – Photovoltaikanlage verbessert Ökobilanz 2015

Heute besuchte der Wirtschaftsminister Gerber Unternehmen in der Region, so auch das Vorzeigeunternehmen Allresist. Über die Entwicklung der Förderpolitik entstand eine lebhafte Diskussion.

11. February 2016/by AllAdmin

Two-layer e-beam resist system with novolacs as bottom resist

For multi-layer applications in e-beam lithography, Allresist offers the highly versatile bottom resist AR-BR 5460/5480. The removal rates of the bottom layer can easily be specifically adjusted by slightly changing the softbake temperature and the developer strength.

19. January 2016/by AllAdmin

Determining the conductivity of Electra 92 layers on glass

The specific conductivity of thin films can be determined with various methods, e.g. by non-contact eddy current mapping or also after a direct contact using the four-point probe method (four-peak measurement).

19. January 2016/by AllAdmin

Alkali-stable positive resist obtained after treatment with HMDS

A large variety of applications include a wet-chemical etching step which very often involves highly alkaline etching baths.

19. January 2016/by AllAdmin

Resist of the month January 2016: Electra 92 has now gone into production!

Electra 92 has passed its baptism of fire by the users very well, and an increasingly large number of satisfied customers provided positive feedbacks with respect to the excellent properties of resist AR-PC 5090.02.

1. January 2016/by AllAdmin

31st issue of the AR NEWS

Content:
1. Innovative new developments presented on the MNE 2015 and the SEMICON Europe:
A case for two – CSAR 62 & Electra 92
2. Alternative to Espacer Electra 92 meets user expectations
2.1 Long shelf life of Electra 92
2.2 CSAR structures on glass, made possible due to Electra 92
2.3 PMMA lift-off structures on semi-precious stone substrates with Electra 92
2.4 Electra 92 for applications on novolac-base resists -
New variant SX AR-PC 5000/91.1 for negative CAR AR-N 7700 on glass
3. PPA-Litho project: First application examples of the new PPA resists
4. Allresist turns 23 years old and rejuvenates
5. Chemnitz seminar “Electron-Beam Lithography“ in the Fraunhofer Institute ENAS

21. October 2015/by AllAdmin

Fachartikel in der Nanotechnologie (Electra 92)

Die Fachzeitschrift “Nanotechnologie” schrieb im Oktober 2015 einen interessanten Artikel über die Erfolgsgeschichte unseres Electra 92.

12. October 2015/by AllAdmin

Manufacture of plasmonic nanostructures with CSAR 62

These nanostructures may e.g. serve as optical antennas for the detection of single molecules. To avoid the undesirable charges on the quartz substrate, Electra 92 was used successfully.

5. October 2015/by AllAdmin

CSAR 62 – Experimental studies on new, sensitive developers

CSAR 62 layers can also be patterned by intensive exposure to UV light. Irradiated films were in this experiment developed with different solvents and the observed sensitivities were compared with each other.

5. October 2015/by AllAdmin

CSAR 62 – Development at low temperatures

The sensitivity of CSAR 62 is strongly influenced by the choice of the developer. In comparison to the standard developer AR 600-546, the sensitivity can be increased almost tenfold if AR 600-548 is used instead.

5. October 2015/by AllAdmin

CSAR structures on glass

The use of a combination of CSAR 62 and the conductive coating Electra 92 in e-beam lithography allows the manufacture of highly complex structures on insulating glass or semi-insulating substrates such as e.g. gallium arsenide.

5. October 2015/by AllAdmin

PMMA lift-off structures on semi-precious stone substrates using Electra 92

Semi-precious stones like sapphire or garnet increasingly gain in importance as substrates for semiconductor industry. Even though these materials have insulating properties, a patterning with electron beam lithography is nevertheless possible with the help of Electra.

5. October 2015/by AllAdmin

Electra 92 variant optimised for applications on novolac-based resists

Novolac-based e-beam resists have other surface properties than e.g. CSAR 62, PMMA, or HSQ resists. Due to a higher solvent content of the conductive resist as for example is the case with SX AR-PC 5000/90.2, these novolac-resists are already moderately attacked.

5. October 2015/by AllAdmin

Conductivity under the application conditions of e-beam lithography

The measured conductivity of resist layers is strongly influenced not only by the temperature but also directly dependent on the air humidity. After a softbake, the now almost anhydrous layer gradually takes up water at room temperature from the ambient air due to the slightly hygroscopic properties of the polymer.

5. October 2015/by AllAdmin

Long-term stability of Electra 92

To assess the long-term stability of Electra 92 (SX AR-PC 5000/90.2), two reference samples were coated on glass (300 rpm, 3 min, softbake at 85 °C for 30 min in the oven) after different storage times of 15 months and 3 months, respectively (refrigerator, 8 °C).

5. October 2015/by AllAdmin

Resist of the month October 2015: E-beam lithography on glass – CSAR 62 and Electra 92

Allresist presented this precise and easy to handle two-layer system already on the MNE (Micro and Nano Engineering) 2015 in Den Haag with great success.

1. October 2015/by AllAdmin

Adaptable two-layer resist AR-BR 5460 for variable lift-off structures

Bottom resist AR-BR 5460 has already been used for a decade in combination with positive (e.g. AR-P 3510) or negative resists (e.g. AR-N 4340) for a large variety of lift-off applications.

21. July 2015/by AllAdmin

Structuring of polyphthalaldehydes with photolithography

PPA layers are sensitive to light and can thus be structured directly by photolithography. Irradiation with light of wavelengths < 300 nm (Hg vapour lamp) results in a cleavage of the polymer chains and the formation of volatile components that partly begin to evaporate even at room temperature.

21. July 2015/by AllAdmin

Poly(phthalaldehyde)-based electron beam resists

A direct positive patterning of PPA layers is possible by electron bombardment. Similar to the irradiation of normally used e-beam resists like e.g. CSAR 62 or PMMA, the electron beam causes a fragmentation of the polymer chains.

21. July 2015/by AllAdmin

Resists for novel applications in lithography – thermally structurable polymers

Within the scope of the Eurostar project PPA-Litho, Allresist currently evaluates innovative high-quality resists on poly(phthalaldehyde) (PPA) basis in cooperation with the company Aglycon, the Joanneum Research in Weiz, and the SwissLitho AG in Zurich.

21. July 2015/by AllAdmin

Ethanol and toluene-resistant photoresist AR-U 4060

Structures of the image reversal resist AR-U 4060 show an increased resistance against organic solvents after flood exposure with subsequent tempering. Ethanol and toluene attack normal positive resist layers quickly, which are consequently dissolved in short time.

21. July 2015/by AllAdmin

Patterning of the conductive protective coating Electra 92

A negative resist (e.g. AR-N 4340) is coated onto the substrate, exposed, and developed. The exposure dose should be chosen as small as possible to provide the desired slight undercut which supports the later lifting.

21. July 2015/by AllAdmin

High resolution on quartz with Electra 92 on HSQ resists

An accurate patterning on quartz substrates is not possible without the use of a conductive coating. Investigations of the company Raith GmbH demonstrated that an HSQ resist XR1541 on a quartz substrate can be patterned with very high quality after coating with Electra 92.

21. July 2015/by AllAdmin

Two-layer photoresist system for water-sensitive substrates

If contact of a substrate with water must be avoided during the patterning process, a two-component photoresist system composed of PMMA resist (bottom layer) and photoresist (top layer) offers an alternative to SX AR-N 4810/1.

21. July 2015/by AllAdmin

Resist of the month Juli 2015: Process-adapted two-layer resist AR-BR 5460

The bottom resist AR-BR 5460 has already been used for a decade in combination with positive (e.g. AR-P 3510) or negative resists (e.g. AR-N 4340) for a large variety of lift-off applications.

1. July 2015/by AllAdmin

Dose-dependent structure size with negative resists

The desired structure size also largely depends on the exposure dose used. In the case of overexposure, structures begin to widen which is particularly pronounced during laser exposure.

20. May 2015/by AllAdmin

Generation of undercut structures with negative resists

With laser direct exposure, a slight undercut of the structures can be generated: The upper part of the layer is more strongly irradiated due to the absorption of the resist and consequently more intensely crosslinked.

20. May 2015/by AllAdmin

Sensitive negative resist for 405 nm laser direct exposure

Negative resist AR-N 4400-10 can be structured with laser direct exposure at an exposure wavelength of 405 nm. Different arrays are shown in the figure.

20. May 2015/by AllAdmin

Negative CAR PMMA resist SX AR-N 4810/1

The principle of chemical amplification could successfully be transferred to PMMA polymers. The new special resist SX AR-N 4810/1 is a chemically amplified photoresist based on PMMA that can be developed anhydrously with organic solvents – a crucial property in the case of moisture-sensitive substrates.

20. May 2015/by AllAdmin

Stabilisation/ hardening of resist films

A large variety of applications require structured resist architectures which achieve long-term stability against organic solvents after a subsequent hardening step.

20. May 2015/by AllAdmin

Alkaline developers for aluminium substrates

Some of our customers use alkali-sensitive aluminium substrates. This leads to problems if the metal surface should not be etched in this process.

20. May 2015/by AllAdmin

New developer for AR-P 5320

In our product information, we recommend developer AR 300-26 for the development of AR-P 5320, our positive photoresist for lift-off applications. A few users however prefer to work with MIF-developers.

20. May 2015/by AllAdmin

30th issue of the AR NEWS

Content:
1. Investment in sun energy – Allresist installed a rooftop photovoltaic system
2. Highly sensitive negative resist for laser direct exposure
3. PPA-Litho-project: Resists for new applications in lithography
4. Further CSAR 62 applications – high-precision rectangular structures
5. New results with Electra 92

21. April 2015/by AllAdmin

Resist of the month April 2015: High-sensitivity negative resist AR-N 4400-10

The negative resist AR-N 4400-10 was structured with a laser direct imaging system at an exposure wavelength of 405 nm. The figures below show different arrays with column diameters varying from 5 to 50 µm.

1. April 2015/by AllAdmin

W+M-Artikel: Das Monopol geknackt

Das Strausberger Chemieunternehmen Allresist hat ein langjähriges Monopol geknackt. Sein neuer Hightech-Lack, der Resist CSAR 62, wird bei der Produktion von Mikrochips der neuesten Generation eingesetzt. Die Kunden sind begeistert. Von Dr. Ulrich Conrad.

3. March 2015/by AllAdmin

Fachartikel in der Nanotechnologie (CSAR 62)

Die Fachzeitschrift "Nanotechnologie" schrieb im August 2014 einen interessanten Artikel über die Erfolgsgeschichte unseres CSAR 62.

22. January 2015/by AllAdmin

Resist of the month January 2015: High temperature-resistant positive resist

After the successful development of negative resist SX AR-N 4340/7 which is temperature-stable up to 350 °C, we can now in addition offer a temperature-resistant positive variant called SX AR-PC 3500/8. This resist may be exposed and ..

1. January 2015/by AllAdmin

Fachartikel im Magazin für Oberflächentechnik

Die Fachzeitschrift "Magazin für Oberflächentechnik" hat unserer Neuentwicklung CSAR 62 in ihrer November-Ausgabe 2014 einen langen Artikel gewidmet.

22. November 2014/by AllAdmin

Water-based resists

The majority of photoresists is almost exclusively soluble in organic solvents like e.g. PGMEA (propylene glycol methyl acetate, German: PMA). But there are exceptions.

27. October 2014/by AllAdmin

NIR-laser structurable photoresists

By adding suitable dyes to negative-working CAR resists, even a patterning beyond the usual wavelength range is possible if pulsed lasers with sufficiently high intensity are used for exposure.

27. October 2014/by AllAdmin

Developer AR 300-35 for alkali-sensitive substrates

The use of aqueous-alkaline developers on alkali-sensitive substrates like aluminium is problematic, because the substrate is similarly attacked during the development step.

27. October 2014/by AllAdmin

Thermostable photoresists

Many applications demand coatings with excellent thermal stability. Structures of the temperature-stable negative resist SX AR-N 4340/6 are able to withstand temperatures of up to 350 °C with high shape accuracy

27. October 2014/by AllAdmin

PMMA protective coating: reduction of cotton candy effect

Since problems may occur when PMMA protective coatings are applied, new ideas emerged how to optimise the coating properties of these resists. So far, protective coatings tend to show under certain circumstances the so-called "cotton candy effect" during spin coating, which means that fine PMMA threads are formed.

27. October 2014/by AllAdmin

Safer solvent PMMA protective coating

The protective coatings AR-PC 503 and AR-PC 504 have been successfully used for many years in aggressive KOH etching procedures. These resists are traditionally produced with the solvent chlorobenzene.

27. October 2014/by AllAdmin

Sensitive negative PMMA resist (CAR)

PMMA resist are mainly used for electron beam applications or as protective coatings in aggressive wet chemical etching procedures. In principle, also a structuring of PMMA layers with deep UV exposure (220-266 nm) is possible, but the sensitivity is in this case low and long exposure times are consequently required.

27. October 2014/by AllAdmin

CSAR 62 Avoidance of particles during large-area exposures

During the exposure and subsequent development of large structures (> 1 µm), occasionally particles are deposited on fully developed surfaces

27. October 2014/by AllAdmin

CSAR 62 lift-off for thick layers

For special applications in which metal layers with a thickness of a few hundred nanometres are to be generated by lift-off techniques, accordingly higher layers are needed.

27. October 2014/by AllAdmin

CSAR 62 thick layers

Intense plasma etchings for the generation of deep etch structures however require significantly thicker resist layers and place special demands on resolution and contrast.

27. October 2014/by AllAdmin

29th issue of the AR NEWS

Content:
1. Opening ceremony of our annex building on time for the 22nd anniversary of Allresist
2. New application results with CSAR 62 (thicker layers)
3. Start of Eurostar project PPA-Litho on 1. November 2014
4. New developments of Allresist

21. October 2014/by AllAdmin

Resist of the month October 2014: Safer solvent

The protective coating AR-PC 504 has proven itself successful many times for our customers in the past six years. Layers of this polymer reliably protect substrates against concentrated bases and acids.

1. October 2014/by AllAdmin

Resist of the month July 2014: Electra 92

Allresist developed a novel polymer based on polyaniline in cooperation with the IDM e.V., Teltow. The new conductive protective coating SX AR-PC 5000/90.2 was already presented in issue 28 of the AR NEWS.

1. July 2014/by AllAdmin

New safer solvent remover AR 300-76

A further new development, the likewise universally applicable remover AR 300-76, is characterized by a much higher flash point of 103°C as compared to AR 600-71.

13. June 2014/by AllAdmin

Aqueous negative resist based on gelatine

In the presence of catalytic iron salts, it is possible to photochemically induce a negative crosslinking of gelatine. Coated substrates are for this purpose exposed and briefly swivelled in diluted hydrogen peroxide solution which acts as crosslinking agent.

13. June 2014/by AllAdmin

Thick CSAR 62

A few applications like e.g. the manufacture of deep etched structures by plasma etching require a processing of thick resist layers. Of major importance in this case is a high sensitivity, especially in electron beam lithography.

13. June 2014/by AllAdmin

Developer for CSAR 62 (AR-P 6200)

For a development of exposed CSAR 62 resist films generally performed by immersion development with development times of approximately 30-60 seconds, developers AR 600-546, 600-548 and 600-549 are well suited.

13. June 2014/by AllAdmin

Laser direct exposure with AR-P 3540

In addition to a structuring with photomasks which is frequently used in lithography, is it also possible to write the structures directly, i.e. without masks, with laser beams.

13. June 2014/by AllAdmin

Chemically amplified, highly sensitive negative e-beam resist SX AR-N 7730/37

With SX AR-N 7730/37, we present a new negative CAR e-beam resist. This resist possesses a very high sensitivity with at the same time high process stability.

13. June 2014/by AllAdmin

Ratio resolution and dose, exemplarily shown for e-beam resist SX AR-N 7530/1

Process-stable negative resist systems which allow resolutions of < 30 nm with sufficiently high sensitivity are of growing interest for applications in electron beam lithography.

13. June 2014/by AllAdmin

Alkali-stable, easily structurable positive resist SX AR-P 5900/8

Resist AR-P 5900/4 is already well established on the market for many years. Structures of this positive resist are characterized by a considerably higher alkaline stability as compared to standard positive resists (e.g. AR-P 3510 or AZ resists).

13. June 2014/by AllAdmin

Improved protective coating SX AR-PC 5000/31

Protective coatings are in most cases composed of novolacs or PMMA polymers. Both polymers ensure a sufficiently high protective effect against mechanical damages as well as sufficiently high resistance against acidic solutions.

13. June 2014/by AllAdmin

28th Issue of the AR NEWS

Content:
1. News about Allresist: Extension for higher production capacities, second-placed entrepreneur
of the Federal State of Brandenburg and Innovation Prize Berlin Brandenburg 2014
2. New Conductive protective coating for e-beam lithography SX AR-PC 5000/90.2
3. E-beam resist SX AR-N 7530/1 for white light applications
4. AR-P 3540 MIF – a resist which can do more! (Progress report by our partners)
5. Allresist on the Semicon China 2014

21. May 2014/by AllAdmin

Resist of the Month Archive: April 2014

We already reported in April 2013 on the CSAR 62 within the scope of our “Resist of the month”. After a fast development phase, sales of this new electron beam resist started in May.

1. April 2014/by AllAdmin

27th issue of the AR NEWS

Themen im Überblick: Erfolgreiches Jahr 2013 für Allresist ; Gründung des German Innovation Center in Changzhou
; Erfolgreiche Einführung des CSAR 62
; Maskblank-Herstellung in Vorbereitung
; Thermostabile Negativ-Resists
; Leitfähiger Lack für die E-Beam-Lithographie
; Allresist auf der Semicon Europe 2013

21. October 2013/by AllAdmin

Adhesive strength of AR 300-80

In order to prevent the above described stripping of the PMMA layer from the wafer, the use of adhesion promoters is strongly recommended. Helpful is also a tempering of the wafers at maximum temperature (if possible > 200°C)

7. October 2013/by AllAdmin

Development of thick negative resist layer

If the negative resist AR-N 4400-50 is utilised, resist layers of >200 µ m can be built up in repeated coating steps (see product information of CAR 44). Decisive for the quality of the layers to be obtained is the bake procedure.

7. October 2013/by AllAdmin

Resist of the Month Archive: October 2013

Resist of the month October 2013: Thermally stable negative resist SX AR-N 4340/6 Our last resist of the month was the thermally stable two-layer system SX AR-N 4340/10 – AR-P 5460 which reliably tolerates temperatures of up to 200 °C.

1. October 2013/by AllAdmin

Chemically enhanced negative resist (Process parameters and resolution)

Process parameters, sensitivity, resolution, edge quality and dimensional stability are exemplarily shown for AR-N 4340. Investigations were performed on 150mm-wafers with Si-surface.

9. July 2013/by AllAdmin

Negative two- layer lift-off system

Positive two-layer systems have been on the market for a long time (see positive two-layer lift-off systems). Now there are also versions with negative resists as top resist. The greatest advantage of this innovation is the higher thermal stability of negative resists.

9. July 2013/by AllAdmin

Solvents in e-beam resists

The beginning of electron beam lithography dates back to the early 1980s when the first PMMA resists were developed, with chlorobenzene as first solvent. This solvent most efficiently dissolves the various PMMAs (with different molecular masses of 50K to 950K)

9. July 2013/by AllAdmin

Resist of the month July 2013: Thermally stable two-layer system – SX AR-N 4340/10 – AR-P 5460

Resist of the month July 2013: Thermally stable two-layer system – SX AR-N 4340/10 – AR-P 5460 In a large variety of lift-off applications, the resist layer is exposed to high thermal loads.

1. July 2013/by AllAdmin

Resist of the month April 2013: Positive e-beam resist CSAR 62 – an alternative to ZEP 520

Resist of the month April 2013: Positive e-beam resist CSAR 62 – an alternative to ZEP 520 Users cherish the specific properties of ZEP 520, while service and prices are rather feared.

1. April 2013/by AllAdmin

Polymers (film formers)

Polymethyl methacrylates (PMMAs) are widely used e.g. in electron beam lithography. PMMAs are produced by polymerisation of methacrylic acid esters in the presence of radical starters

20. March 2013/by AllAdmin

Adhesion promoter HMDS and diphenylsilanediol (AR 300-80)

The adhesion of resists to different substrates varies. Many substrates like e.g. silicon, silicon nitride and base metals (like aluminium, copper) show generally good resist adhesion features,

28. February 2013/by AllAdmin

Positive polyimide one-layer resist

Polyimides are produced by polycondensation of tetracarboxylic dianhydrides and diamines. For highest thermal strain only polyimides are suitable which contain aromatic building blocks in the polymer chain.

27. February 2013/by AllAdmin

Collapse of extreme high-resolution e-beam resist structures

A typical problem arising from an extreme resolution at an aspect ratio of > 10 is the collapse of bar structures. In Fig. 1, 10-nm bars with a pitch of 50 nm are displayed. These structures were realised with CSAR 62 (SX AR-

27. February 2013/by AllAdmin

New procedure for the spray coating of deep topologies with SX AR-P 1250/20

In the CiS Institute for Microsensors, deep silicon etch grooves are structured for the fabrication of customer-specific components. For this purpose, a coating procedure via spray coating was developed.

27. February 2013/by AllAdmin

Aluminium structures developed directly

The fabrication of aluminium structures generally involves the production of a resist mask with subsequent wet-chemical etching. The more elegant procedure of direct development can be applied if the negative resist SX AR-

27. February 2013/by AllAdmin

AR-N 7700, 4 µm thick, proximity effect

The general aim of electron beam lithography is to achieve a maximum resolution, and therefore mostly very thin layers are used (50 - 500 nm). In a few cases however also very small structures with high aspect ratio are of interest.

27. February 2013/by AllAdmin

Photoresist coatings on Teflon substrates

Teflon or similar products are, due to their extreme surface properties, utilised for applications in which a structuring of the Teflon is sometimes desirable. The hydrophobic surface properties however impede the coating with resist,

27. February 2013/by AllAdmin

Diffractive optics with the “analogous“ e-beam resist

Allresist designed an e-beam resist which produces, depending on the respective exposure dose used, a three-dimensional resist profile.

27. February 2013/by AllAdmin

Negative polyimide photoresist

As an alternative to the positive polyimide resist (SX AR-PC 5000/82.7) which is already a polyimide in dissolved form and thus requires no curing process (see "Positive polyimide resist")

27. February 2013/by AllAdmin

Exposure

Contact exposure refers to a process in which a photo mask and a substrate are brought into direct contact. This procedure leads to the best resolution of all shadow projections.

27. February 2013/by AllAdmin

26th issue of the AR NEWS

Content:
1. Recognition for the Ludwig Erhard Prize winner Allresist
2. CSAR 62 – the future alternative for the ZEP resist
3. NIR-resist in the development – first successes

21. February 2013/by AllAdmin

Resist of the month January 2013: Negative p hotoresists SX AR-N 4340/8 – a resist for laser interference lithography (LIL)

Resist of the month January 2013: Negative p hotoresists SX AR-N 4340/8 – a resist for laser interference lithography (LIL) Well-ordered structures across an entire wafer can be produced (see image 3)

1. January 2013/by AllAdmin

25th issue of the AR NEWS

Content:
1. 20 years of Allresist – a development from MBO to a business of excellence
2. Successful assessment during a site visit for the Ludwig Erhard Prize
3. VEGAS project submitted
4. Our new developments – first results

21. October 2012/by AllAdmin

Resist of the month October 2012: Negative photoresists AR-N 4400 – with optimized bake regime

Resist of the month October 2012: Negative photoresists AR-N 4400 – with optimized bake regime For the new project VEGAS (see AR NEWS, 25 th issue, October 2012), columnar resist structures with a thickness of 10 to up to 60 µm are required.

1. October 2012/by AllAdmin

Two-layer PMMA e-beam resist system for high-resolution lift-off

For the lift-off of high-resolution structures in a two-layer process, PMMA resists (90K and 200K) were adjusted to yield a film thickness of 90 nm to 100 nm. This resist system is particularly well suited for the fabrication of sub-

21. September 2012/by AllAdmin

Wet chemical etching

In wet-chemical etchings, the chemical bonds of the material to be processed are cleaved by mostly aggressive etch media and converted into soluble substances.

Wet-chemical etching procedures thus place very high demands on the protective resist layer. Decisive process parameters are, in addition to the choice of a suitable resist, the etching medium itself, the duration of the etching step and the etching temperature (which determines the reaction speed). Another important aspect concerns the adhesion properties of the resist on the substrate to be etched. An insufficient adhesion of the resist to the substrate may result in the detachment of the resist layer which renders the substrates unusable for any further applications. Adhesion problems and cracks in the resist layer frequently often appear at first at resist edges, since local heat and gas development lead to an additional mechanical load in these areas. Especially in the case of HF-containing etchings, additional large-area detachments of the resist are possible due to the diffusion of fluoride ions through the resist layer; the substrate surface is consequently attacked. Resist adhesion can generally be improved by a suitable pre-treatment of the substrate (adhesion promoter) and an optimised process management (sufficiently high resist thickness, adapted soft-bake and PEB, possible final final-hard bake).

Distinguished are anisotropic etching (rate-limited etching in which the activation energies are different for each crystal plane as in the case of Si etching with concentrated, hot KOH) and isotropic etching which occurs with amorphous materials (glasses, metals). In the case of isotropic etching, an under-etching of the resist layer cannot be avoided even if resist adhesion is optimal. If mass transport (diffusion of active components and etched products) does not limit the etch rate, a lateral under-etching occurs in proximity to the substrate surface which is comparable to the etching depth.

Specific etching mixtures are used for each material/substrate, and resists have to be selected with regard to their compatibility with the etching solution. After wet-chemical etching, intensive and multi-stage rinsing with DI water is required. These rinsing steps completely remove any etching solution which penetrated into the resist layer and prevents possible later resist damages. Insufficient rinsing may lead to a concentration of the etching solution during the final drying step, which then results in crack formation and altered/poor removing properties.

Novolac-based resists generally show a good stability against non-oxidizing acids and corrosive iodine solutions (KI*I2). Concentrated hydrochloric acid is thus generally no problem, while concentrated nitric acid or concentrated sulphuric acid solutions strongly attack the resist layers.

Diluted hydrofluoric acid (concentration < 6 %) is well tolerated, but more concentrated HF solutions causes problem with respect to the adhesion properties of the resist which are due to a diffusion of F– ions. The concentration of „free“ F– ions can however be reduced if NH4F-buffered HF etch is used (BOE process). At the same time, the formation of highly reactive HF2– ions induces a considerable increase of the etch rate and a more controllable, more homogeneous etching process. Novolac-based resists show a significantly higher stability against buffered HF solutions.

Novolac-based resists are quickly attacked in strongly alkaline etching solutions. PMMA (resist AR-PC 503) is well suited for a use as backside protection, e.g. for etchings with hot, concentrated KOH. The substrates (also the edges!) must however be coated without any defects in order to avoid a rapid detachment of the protective layer due to under-etching.

31. August 2012/by AllAdmin

Alternatives for NMP-based removers

On September 25, 2009, regulation (EC) No 790/2009 amending EC-GHS regulation (No 1272/2008) on the classification and labelling of substances and mixtures came into force. With this regulation also the new classification of N-

31. August 2012/by AllAdmin

High-resolution PMMA one layer resist

Utilizing SX AR-P 640/2 (PMMA 90K) as one layer system, an even higher resolution can be achieved if process parameter are varied, in particular the exposure dose.

31. August 2012/by AllAdmin

UV-structuring of PMMA resists

PMMA resists can also be patterned using UV-lithography, but only at exposure wavelengths of 200 – 270 nm (deep UV light). Typically used is the wavelength-range of the lowest line of high-pressure mercury lamps at 254 nm.

31. August 2012/by AllAdmin

Polyimide two-layer systems

In certain applications it is desirable to keep the original properties of a polymer unchanged, e.g. without addition of light-sensitive components like for example for a use as moisture sensor.

31. August 2012/by AllAdmin

Spray resists for different topologies (negative)

Allresist furthermore offers various negative-tone resists for spray coating applications which are described in detail in this section (see Spray resists for different topologies (positive and negative)

31. August 2012/by AllAdmin

Spray resists for different topologies (positive and negative)

Spray resists available to date (AZ 4999) are designed for extreme topologies, which means that even vertical silicon trench sidewalls can be covered with resist. These excellent features however come at a price:

31. August 2012/by AllAdmin

Resist for 488 nm exposure wavelength

General exposure wavelengths for broadband UV-lithography are in a range between 300 nm and 450 nm, which includes the important lines of high-pressure mercury lamp at 436 nm (g-line).

31. August 2012/by AllAdmin

Chemical dry etching

Chemical dry etchings fall into two categories depending on the etching principle. 1. A more chemical etching refers to a process in which the substrate is attacked by radicals and converted into volatile compounds.

31. August 2012/by AllAdmin

Thinner

Correct dilution of resists (see “Dilution of resists”) Resists are mainly composed of solvents. The majority of photoresists and the negative-tone e-beam resists utilize PGMEA (PMA)

15. August 2012/by AllAdmin

Process procedure photoresists

When new and clean substrates (wafers) are used, a heating at approximately 200 °C for several minutes (2-3 min, hot plate) is sufficient for drying. Substrates should however subsequently be processed quickly.

30. July 2012/by AllAdmin

Process procedure e-beam resist

Process procedure e-beam resist
Development of PMMA films PMMA films can only be developed with solvent-based developers. Aqueous-alkaline PMMA developers will not attack PMMA - PMMA is even used as protective coating in the presence of strongly alkaline solutions.

30. July 2012/by AllAdmin

Development procedures

Developers are designed to remove exposed areas of positive-tone resists and unexposed areas of negative-tone resists without leaving any residuals. The respective other areas of the wafer are ideally not attacked by the developer and remain with a film thickness identical to the initial value.

30. July 2012/by AllAdmin

Removers in general

Removers have the task to completely dissolve all resist structures or residues after the respective techonological process step (doting, etching or others) is finished.

30. July 2012/by AllAdmin

UV-curing

Photoresist structures of standard resists possess a softening point of 115 - 130 °C. During subsequent thermal processes (plasma etching, sputtering or others), these temperatures are easily exceeded.

30. July 2012/by AllAdmin

Stopper

Stoppers in the classical sense are mainly used for electron beam lithography with PMMA resists. These substances have the function to interrupt the development process after a development of exposed PMMA films and to cleanly rinse off the developer solvent which now contains residual PMMA.

30. July 2012/by AllAdmin

Principle and functioning

Positive resist The addition of photoactive compounds (PACs, naphthoquinone diazide (NQD)) to alkali-soluble novolacs reduces the alkali-solubility of resists films.

24. July 2012/by AllAdmin

Resist for near infrared (NIR)

With the development of photoresists for an exposure in the wavelength range of 500 to 1100 nm using laser light, new procedures became possible. Lithographic processes at an exposure wavelength greater than 480 nm are not possible with standard photoresists.

16. July 2012/by AllAdmin

Two-layer resist system for hydrofluoric acid etching

Hydrofluoric acid etchings, even those in highly concentrated acids (48%), are technologically used despite the high risk involved with HF applications.

16. July 2012/by AllAdmin

Protective coating for KOH-etching

Protective coatings AR-PC 503 and 504 are able to withstand the presence of 40%, 85°C warm KOH for several hours. The polymer PMMA is not attacked under these conditions. These resists can consequently be used to protect front and back surface of wafers during deep silicon etching.

16. July 2012/by AllAdmin

Alkali-stable and solvent-stable negative resist

Most novolac-based photoresists are characterized by high etch stability in the presence of acids (except in highly concentrated oxidizing acids or in concentrated hydrofluoric acid

16. July 2012/by AllAdmin

Temperature-stable negative resist

New aqueous-alkali soluble polymers may even outperform novolacs in certain features. Standard novolacs generally melt in a range between 115–130°C. The thicker the resist film, the higher is the impact of this feature on the resist structure.

16. July 2012/by AllAdmin

Other resist components

Solvents are the main component of all resists, with solvent contents ranging from 50% (thick resists) to up to 99% (spray resists).

16. July 2012/by AllAdmin

Ageing of developer

Aqueous-alkaline developers are subjected to ageing, due to an uptake of CO 2 from the air. Buffered aqueous-alkaline developers ( AR 300-26, -35 ) are more stable in this respect than developers of the AR 300-40 -series containing TMAH.

13. July 2012/by AllAdmin

Positive polyimide resist for e-beam-lithography

First experiments with our SX AR-P 5000/82.7 using e-beam lithography clearly demonstrated that this resist can easily be patterned which offers the possibility to generate nanostructures which are thermally stable up to 350 °C.

13. July 2012/by AllAdmin

High-resolution negative e-beam resist

A process-stable, sufficiently sensitive e-beam resist with a resolution of about 30 nm is urgently needed to accelerate the progress in electron beam lithography.

13. July 2012/by AllAdmin

Lift off (one layer – two layer)

Two procedures are principally possible to manufacture e.g. conducting paths: 1. Etching technique: A thin metal film (e.g. aluminium) is deposited on a wafer (evaporation or sputtering)

13. July 2012/by AllAdmin

Composition of photoresists

Photoresists are particularly employed in microelectronics and in microsystems technology to generate µm- and sub-µm structures.

13. July 2012/by AllAdmin

Photosensitive components

The p hoto sensitive components of our positive photoresists belong to the group of naphtho qu inone d iazides (NQD).

13. July 2012/by AllAdmin

Cross linker

The patterning of negative resists is based on the stabilization of exposed areas in the presence of cross-linking agents. Radical starters like e.g. azo-bis(isobutyronitrile) (AIBN)

13. July 2012/by AllAdmin

Storage and ageing

Photoresists are light-sensitive, their properties change in the presence of light or elevated temperatures. Resists age during storage and are therefore supplied in light-protected amber glass bottles,

13. July 2012/by AllAdmin

Sensitive, etch-stable negative e-beam resist for processes without yellow light

The success story of electron beam lithography began in the 1980th with the development of the first PMMA resists. These resists are absolutely light-insensitive in the UV-wavelength range above 300 nm.

13. July 2012/by AllAdmin

24nd issue of the AR NEWS

Content:
1. Allresist is now employee champion and applies for the Ludwig Erhard price
2. Results of the new e-beam resist AR-N 7520
3. NIR-coatings in development – fist successes
4. Our new developments – first results

21. April 2012/by AllAdmin

1. What are e-beam resists composed of, and how do they work?

E-beam resists (electron beam resists) are designed for electron beam and deep UV applications for the fabrication of highly integrated circuits, mainly for mask fabrication. They are employed in electron beam direct writing and multilayer processes.

23. August 2008/by AllAdmin

2. For how long are e-beam resists stable, and what are the optimal storage conditions?

PMMA- and copolymer e-beam resists are not light-sensitive in the visible UV range, they consequently don’t react to light exposure (no safe yellow light required) and are substantially less temperature-

22. August 2008/by AllAdmin

1. What are photoresists composed of, and how do they work?

Photoresists (also photo coatings) are primarily used in micro electronics and micro system technologies for the production of µm- and sub-µm structures. These resists are generally deposited by spin coating in a range between 250

21. August 2008/by AllAdmin

3. What is the optimal pre-treatment of substrates for e-beam resist application?

If new and clean substrates (wafers) are used, a bake at approximately 200 °C for a few minutes is sufficient in order to dry the substrates, which however then have to be processed quickly.

21. August 2008/by AllAdmin

2. For how long are photoresists stable, and what are the optimal storage conditions?

Photoresists are light-sensitive, they are affected by light exposure and high temperatures, and age-related changes occur during storage. Resists are therefore filled in light-protected amber glass bottles,

20. August 2008/by AllAdmin

4. How high is the adhesion strength of e-beam resists to different wafers?

Adhesion between substrate and coating is a sensitive feature of a resists, which is also true for e-beam resists. PMMA- and copolymer resists are however significantly less prone for adhesion problems than e-

20. August 2008/by AllAdmin

3. How may age-related changes influence the quality of a photoresist?

During storage, red azo dyes develop due to a thermal chemical reaction of the light-sensitive component with the novolak, causing a darkening of the resist. Even small amounts of the dye lead to darkening,

19. August 2008/by AllAdmin

5. How are e-beam resists exposed? How can the optimum exposure dose be determined?

By using very short-wavelength electrons for the exposure of the resists, an excellent resolution of up to 2 nm can be achieved (spot beam). Exposure is carried out by conventional e-beam equipment following the principle of direct writing or shaped beam procedure.

19. August 2008/by AllAdmin

4.What is the optimal pre-treatment of substrates for photoresists?

If new and clean substrates (wafers) are used, a bake at approximately 200 °C for several minutes is sufficient for drying, but the substrates have to be processed quickly afterwards.

18. August 2008/by AllAdmin

6. Which developers are optimal for e-beam resists, and how do factors like developer concentration and temperature influence the result?

During development, a positive tone resist film is patterned by a removal of exposed areas, while unexposed areas are removed when negative resists are used. To achieve reproducible results,

18. August 2008/by AllAdmin

5. What are the adhesion features of photoresists on different wafers?

Adhesion between coating and substrates is a very sensitive feature. Smallest changes of the cleaning procedures or the process parameters can have a fatal impact on the adhesive strength.

17. August 2008/by AllAdmin

7. How can e-beam resist films be removed again?

For the removal of all e-beam resist coatings baked at lower temperatures (softbake), polar solvents may be used such as e.g. the recommended thinner AR 300-12 or AR 600-01, 600-07,

17. August 2008/by AllAdmin

6. What are the optimum coating parameters for photoresists in order to achieve good film images?

Prior to the coating procedure, resists have to be adjusted to the temperature of the (preferably air-conditioned) working area. If the resist is too cold, air moisture may precipitate on the resist.

16. August 2008/by AllAdmin

8. Which resolutions do e-beam resists achieve?

With respect to the achievable resolution, purely academic resolution values and industrially utilisable values represent two quite different aspects. Theoretically, resolutions of 2 nm are possible (single electron spot)

16. August 2008/by AllAdmin

7. Why may air bubbles develop in photoresist films, and how can they be avoided?

Bubbles after spin deposition are in most cases air bubbles, e.g. if the resist bottle was agitated or moved around, or if the resist was diluted prior to the coating step. Coating procedures performed immediately after bottle opening,

15. August 2008/by AllAdmin

9. How high is the plasma etch resistance of e-beam resists?

Electron beam resists of the AR 6000 and AR 7000 production line display quite different etch resistance features in dry etch processes such as e.g. argon sputter and CF 4 . Novolak-

15. August 2008/by AllAdmin

8. What is the function of the softbake of photoresist films after the coating?

Just recently coated resist films still contain a substantial amount of residual solvent, depending on the respective film thickness. The subsequent bake step at 90 – 100 °C is performed in order to dry the resist films,

14. August 2008/by AllAdmin

10. How high is the etch resistance of e-beam resists in the presence of strong acids?

Concentrated oxidising acids (sulphuric acid, nitric acid, aqua regia 1) , piranha 2) ) attack resist films already at room temperatures and are often used as remover for persistent resist structures.

14. August 2008/by AllAdmin

9. How are photo resists exposed, and how can the optimum exposure dose be determined? How long can coated and exposed substrates be stored prior to exposure?

The exposure is performed using masks in suitable exposure systems such as e.g. steppers (i-, g-line), mask aligners or contact exposure systems in the appropriate spectral working range.

13. August 2008/by AllAdmin

11. How high is the solvent resistance of e-beam resist films?

With respect to the source materials used, e-beam resists fall into two different categories: PMMA resists (AR-P 6000) Novolak resists (AR-N/P 7000) » The general rule is that with increasing bake-

13. August 2008/by AllAdmin

10. Which developers are optimal for photoresist, and how do factors like developer concentration and temperature influence the result?

During development, a positive tone resist film is structured by a removal of exposed areas, while unexposed areas are removed when negative resists are used. To achieve reproducible results,

12. August 2008/by AllAdmin

11. How can resist coatings be removed again?

For the removal of softbaked coatings, polar solvents such as e.g. the respective resist thinner AR 300-12 (methoxy propyl acetate = PGMEA) and the remover AR 600-70 (acetone-based)

11. August 2008/by AllAdmin

12. What is the application range of protective coatings?

Protective coatings are available for a large variety of applications, e.g. for the protection of wafer-backsides: or mechanical protection during transport

10. August 2008/by AllAdmin

13. How do image reversal resists work?

With image reversal resists such as AR-U 4000, positive or negative tone images can be generated of the optical transmitted pattern depending on the manufacturing process. If the resist is processed according to the general protocol for positive resists without any additional steps,

9. August 2008/by AllAdmin

14. How can undercut patterns (lift-off structures) be produced in one- or two layer systems?

A variety of one- or two layer systems are available which generate undercut patterns. For example, AR-P 5350 is a one layer system suitable for the production of metallic vapour phase structures.

8. August 2008/by AllAdmin

15. How can thick films of > 10 µm be processed in an optimal way?

Coating: As a general rule for the coating with thick positive and negative tone resists, resists should be left undisturbed for several hours up to one day before processing ( » Question 6 Optimum coating parameters,

7. August 2008/by AllAdmin

16. Which resolution and which contrast can be obtained with photoresists?

The resolution of resists is influenced by several parameter such as e.g. the type of mask liner used, most of the respective NA (numerical aperture), film thickness, exposure wavelength,

6. August 2008/by AllAdmin

17. How high is the plasma etch resistance of photoresists?

Photoresists of the AR-product lines 3000 to 4000 display a very high etch resistance due to the polymers which are used for their production. This is especially the case for dry etch processes such as e.

5. August 2008/by AllAdmin

18. How high is the etch resistance of photoresist in the presence of strong acids?

Concentrated oxidising acids (sulphuric acid, nitric acid, aqua regia 1) , piranha 2) ) attack resist films already at room temperatures and are often used as removers for persistent resist structures.

4. August 2008/by AllAdmin

19. Which photoresists are suitable for hydrofluoric acid (HF) etching?

The positive tone photoresist X AR-P 3100/10 is extremely adhesion enhanced and thus suitable for HF etching of up to 5 % HF. In particular on glass or silicon oxide, a pre-treatment of substrates with the adhesion promoter AR 300-

3. August 2008/by AllAdmin

20. How high is the solvent resistance of photoresist films?

With respect to the source materials used, photoresists fall into two different categories: PMMA resists (protective coating AR-PC 5000/4, -503, 504, SX AR-N 4800) Novolak resists (AR-

2. August 2008/by AllAdmin