Hydrogen silsesquioxane as a high resolution negative-tone resist for extreme ultraviolet lithography

Abstract

Hydrogen silsesquioxane (HSQ) was evaluated as a high resolution negative-tone photoresist for extreme ultraviolet (EUV) lithography. The following imaging properties of HSQ were evaluated in EUV exposure: sensitivity, contrast, resolution, and line edge roughness (LER). In this article we report that HSQ has a sensitivity of 11.5mJ∕cm2 with a contrast of 1.64 in EUV exposure and is able to resolve 26nm dense lines (70nm thick film) with a LER of 5.1nm (3σ). These results, especially with regard to the sensitivity and low line edge roughness, imply that this class of materials may hold distinct advantages over traditional chemically amplified resists and should be further explored for application in EUV lithography.