Polyhydroxystyrene Carbonate Esters for High Sensitivity Photoresists Having Autodecomposition Temperatures > 160°

Abstract

There are particular polymeric materials having acid labile groups pendant to the polymer backbone which can be used to produce resist structures having autodecomposition temperatures greater than 160°C. The increase in autodecomposition temperature of the resist is achieved by selecting acid labile groups which upon acid catalyzed deprotection generate less stable intermediate carbonium ions than the t-butyl carbonium ion. Acid labile groups that provide increased autodecomposition stability include those capable of forming secondary aliphatic and deactivated secondary benzylic carbonium ion intermediates. There must be a hydrogen on a carbon adjacent to the carbonium ion in order for elimination of an alkene and a proton to occur and continue the chemical amplification process. The acid labile pendant groups can be part of a polystyrene homopolymer or part of copolymers containing styrene and maleimide units.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.