A Positive Tone Plasma-Developable Resist Obtained by Gas-Phase Image Reversal

This paper describes a gas-phase image reversal process that generates a positive tone, plasma-developable image from a chemically amplified photoresist system. This system is based on the catalytic photogeneration of phenolic hydroxyl groups within the resist film that react, in subsequent steps, with either a silylating agent or an isocyanate that is delivered in the gas phase. This forms silyl ethers and carbamates within the polymeric film. The regions of the film containing the organosilicon species are not etched in an oxygen plasma environment. Correspondingly, the carbamate regions of the film are rapidly etched in an oxygen plasma. The overall process results in a positive tone image after development in an oxygen plasma. © 1992, American Chemical Society. All rights reserved.