Polymer design for 157 nm chemically amplified resists

Abstract

Based on UV measurements at 157 nm of in-house fluoropolymers we have selected α-trifluoromethylacrylate and norbornene beating a pendant hexafluoroisopropanol group as our building blocks for 157 nm resist polymers. Polymers consisting of these repeat units have an optical density/μm of 3 or below at 157 nm. We have found that the α-trifluoromethylacrylate derivatives conveniently undergo radical copolymerization with norbornenes, which has provided a breakthrough in preparation of our 157 nm resist polymers. This approach offers flexibility and versatility because an acidic moiety or acid-labile group can be placed in either acrylate or norbornene repeat unit. Other platforms of interest include all-acrylic, all-norbornene, and acrylic-styrenic polymers. © 2001 SPIE - The International Society for Optical Engineering.