Theoretical and Experimental Study on the Silylation of Alcohol Units in ArF Lithography Resists.

Abstract

Molecular orbital calculations at the MP-2 (the second-order MOller-Plesset perturbation theory) level predict that the activation energy of silylation at the alcohol is 22.1 kcal/mol when dimethylsilyldimethylamine (DMSDMA) is used as a silylation agent. This value is in good agreement with the value of 25.0 kcal/mol obtained from an Arrhenius plot for the silylation of polyvinylalcohol (PVA) with DMSDMA.ArF flood-exposure measurements also show that PVA exhibits negative-tone lithographic performance when it is used in the silylation process. Taking advantage of the nonlinearity of the Arrhenius plot should make it possible to enhance sensitivity without using chemical amplification.