Resist aspect ratio has always been an issue for lithographic processes. Smaller CD forces the use of thinner resist films, but dry etch needs a certain amount of thickness in the resist. Various techniques have been proposed and researched to overcome these single-layer resist limitations. Bilayer Si-containing resists are a technique of interest and a strong candidate to replace CVD processes. In this paper, we have characterized bilayer resists and their dry-develop processes, and sought possible uses for advanced lithography, especially by using a thin film (70 nm-90nm). Bilayer resist dry-develop consists of a film shrink as in an exposure reaction with an early-stage resist surface oxidation. We discuss material requirements for this purpose and provide some after-dry-develop images with small CD.
Advances in Resist Technology and Processing XXIII pt.2
【关键词】bilayer resist;Si-containing resist;193nm;photolithography;