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.
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.
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.
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.
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
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.
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.
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.
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).
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.