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.
If the specific properties of PMMA structures are desired e.g. for transparent coatings, negative PMMA resists can be used. Allresist offers for these applications resist X AR-N 4800/16. This resist can be structured in the deep-UV and i-line range (365 nm) but has, like all conventional PMMAs, only intermediate sensitivity.
Hence, a more sensitive PMMA-variant was sought. The principle of chemical amplification could successfully be transferred to PMMA polymers. The new chemically amplified formulation is characterised by a very good sensitivity in the wavelength range of 300-410 nm, but even g-line exposure (436 nm) is well possible. Resist thicknesses of up to 5 µm can be realised with the new experimental sample SX AR-N 4810/1. The developer is composed of an anisole solvent mixture. The resist can thus also be used for the structuring of water-sensitive substrates, since no contact with aqueous process chemicals occurs. The resist is thus also suitable for the production of waveguides or applications in microsystems technology.
Abb. 1 5-µm bars with SX AR-N 4810/1