Preparation and characteristics of a chemically amplified silicone-based negative resist.

Abstract

The characteristics of a chemically amplified silicone-based negative resist, composed of alkali-soluble silicone polymer and an acid generator, have been studied. This polymer is obtained through a sol-gel reaction of a mixture of phenyltrimethoxysilane and 2-(3, 4-epoxycyclohexyl)ethyl trimethoxysilane and has numerous silanol groups that make it alkali-soluble. The resist's chemistry is based on the acid-catalyzed condensation of the silanol groups during post exposure baking. The CSNR includes silicon atoms in such abundance that it exhibits high resistance to oxygen reactive ion etching and can be used as a top imaging layer of a two-layer resist system. Using a KrF excimer laser stepper, 0.25-μm lines-and-spaces patterns can be fabricated with a two-layer resist system. The sensitivity depends on the structures of acid generators (AG's). A resist with triphenylsulfonium triflate showed the highest sensitivity in this study.