Direct-writing in self-developing resists using low-power, cw, ultraviolet light.

Direct-writing of mircon-sized features in self-developing photoresists is demonstrated using less than 1mW of cw ultraviolet light at 257 nm. No energy density or intensity thresholds for ablation are observed. Ablation depth depends only on the deposited energy density and is independent of the rate of deposition; that is, the self-developing process is reciprocal. We have determined that an environment containing oxygen is necessary for complete self-developing in the absence of 0 (2) the process is self-limiting. Patterns created in poly (methyl methacrylate) have been faithfully reproduced into silicon substrates using reactive-ion etching.