Acid-breakable-resin-based chemical amplification positive resist for 0.1-μm-rule reticle fabrication: design and lithographic performance

Abstract

We have designed a new chemical amplification (CA) positive resist for O.1-im reticle fabrication. This positive resist consists of an acid-generator, an acid-diffusion controller, and an acid-breakable (AB) resin that can be converted to initial polyphenol units by an acid-catalyzed reaction. In the exposed region, main-chain scission of the AB resin matrix produces nearly mono-dispersed fragments (the polyphenol). This complete fragmentation results in an extremely high dissolution rate with an aqueous-base developer (tetramethylammonium hydroxide: 2.38 wt%). The AB resin-based resist enabled fabrication of scumfree 0. 15-rim line-and-space patterns on a CrOx plate by using a 50-kY electron-beam reticle writer (I-IL series). The line-edge roughness of patterns delineated by this resist (<10 nm) was less than half that for previously developed novolak-resin-based CA resists (RE series: >30 nm).