Thermally stable photoresists with high sensitivity

US4939070A · kind A · utility

Inventors

• William R. Brunsvold · Poughkeepsie, US
• Ming-Fea Chow · Poughquag, US
• Willard E. Conley · San Diego, US
• Dale M. Crockatt · Somers, US
• Jean M. J. Frechet · Oakland, US
• George J. Hefferon · South Salem, US
• Hiroshi Ito · San Jose, US
• Nancy Iwamoto · Ramona, US
• Carlton G. Willson · Austin, US

Key dates

• Filing date: Jul 7, 1988
• Grant date: Jul 3, 1990
• Expiry date: Jul 7, 2008

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S430/168
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present invention discloses particular lithographic polymeric materials and methods of using these materials, wherein the polymeric materials have acid labile or photolabile groups pendant to the polymer backbone. The polymeric materials are sufficiently transparent to deep UV radiation to permit deep UV imaging, can be used to produce resist structures having thermal stability at temperatures greater than about 160.degree. C., and are sufficiently resistant to excessive crosslinking when heated to temperatures ranging from about 160.degree. C. to about 250.degree. C. that they remain soluble in common lithographic developers and strippers. The present invention also discloses resists comprising substituted polyvinyl benzoates which, after imaging, exhibit unexpectedly high thermal stability, in terms of plastic flow. These resists cannot be imaged using deep UV because they exhibit such a high degree of opacity below 280 nm; however, they are useful as the top, imaging layer in a bilayer resist process wherein the top layer acts as a mask during deep UV exposure of the bottom layer.