Study of bi-layer silylation process for 193 nm lithography

Abstract

The top surface imaging (TSI) process has been studied in order to extend the limit of photolithography down to 0.10 um or smaller dimensions using 193 nm or shorter wavelengths(1)-(10). We have been evaluating a bi-layer silylation process as one of the approaches to improve the lithographic performance of the silylation process. In this paper, we focus on the line edge roughness (LER) of the bi-layer silylation process, which is thought to be one of the serious issues limiting the lithographic performance of the silylation process. We chiefly investigated the effect of process conditions and the silylation resist material itself, and found several factors affecting the LER, such as the silylation film thickness, pre-baking conditions, the break-through (BT) etching conditions and the amount of cross-linker used for the chemically amplified (CA) resist. After optimization of these factors, the pattern quality after the dry-development was remarkably improved. The 0.11 um L/S patterns were well fabricated and the LER was improved. © 1999 TAPJ.