Study of bilayer silylation process for 193 nm lithography using chemically amplified resist

Abstract

The top surface imaging process has been studied in order to extend the limit of photolithography down to 0.10 μm or smaller dimensions using 193 nm or shorter wavelengths. We have been evaluating a bilayer silylation process as one of the approaches to improve the lithographic performance of the silylation process. In this article, we focus on the critical dimension controllability of the bilayer silylation process using a chemically amplified (CA) resist. The application of a CA resist is thought to be one of the promising approaches to increase the photospeed of the silylation process for practical applications. We investigated the effect of process issues due to the CA resist, and evaluated the lithographic performance of this silylation process. The 0.13 μm line and space (L/S) patterns were generated by 5 mJ/cm2 exposure energy, and the 0.11 μm L/S patterns could be generated without using any resolution enhancement techniques. Moreover, by applying an off-axis illumination exposure technique using an attenuated phase shift mask, the 0.10 μm L/S patterns were successfully fabricated with a sufficient process window.