Newly developed alternating-copolymer-based silicon containing resists for sub-100nm pattern fabrication

摘要

Silicon containing bi-layer resist systems for 193nm lithography have been developed for sub-100nm pattern fabrication. Lithographic characteristics of thin film top layer resist show the advantages of high resolution and wide process window. Thick under-layer covers substrate topography with minimum reflectivity and provides sufficient etch resistance for substrate etching. Alternating-copolymers have been employed as backbones of silicon containing resists polymers. Several kinds of functional silicon containing olefins have been synthesized and polymerized to form alternating copolymers. Structural properties of alternating copolymer and hydrophobicity of the silicon containing groups effectively reduced micro swelling in developer and minimized line edge roughness. Discrimination enhancement and acid diffusion control were investigated to achieve high resolution and small proximity pattern size bias. As a result, rectangular 100nm dense line patterns with small line edge roughness are delineated by the newly developed silicone containing resist, using 193nm scanner of NA value of 0.68 and COG-Mask. Characteristics of oxygen reactive ion etching resistance onto the new alternating polymers will be also discussed.