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.

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.

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).

Use of CSAR 62 for the manufacture of nanostructures on GaAs

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.

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).

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.

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.

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.

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).

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.