New system for fast submicron optical direct writing

Abstract

We report on a new system for submicron lithography by fast laser direct writing, where a programmable phase modulating spatial light modulator (SLM) is imaged onto the water using flash on the fly exposure with an excimer laser light source. A SLM with 512×464 pixels has been developed and fabricated using a CMOS active matrix and a reflective, deformable viscoelastic layer on top. Using this light modulator for image generation a demonstrator exposure tool for 0.6μm minimum feature size has been set up and tested including all the components necessary for the exposure of a complete lithographic layer from CAD layout data. The demonstrator is shown to give good quality 0.6μm photoresist pattern at a throughput of roughly one 4″-wafer per hour. Based on the demonstrator results we are designing and setting up a prototype of a production tool with an increased throughput of up to nine 6″-wafers per hour including an automatic alignment system and an automatic wafer handler.