High throughput electron beam lithography on insulating substrates for photonic devices

We have developed an all-polymer procedure for sub-microscale large area patterning of fused silica plates based on electron beam lithography. The procedure relies on the use of a high sensitivity resist, negative tone epoxy-based SU-8 and a conducting polymer, a doped PDOT, as the electron discharge layer. The chemically amplified resist SU-8 allows for a five-fold increase in exposure speed as compared to standard PMMA, and the PDOT layer makes it possible to avoid the time-consuming deposition of a metallic layer and its critical removal. Gratings of stripes and pillars, possibly useful for the realization of photonic devices, are demonstrated.