Ultra Thin Film Resist for Low Energy E-beam Projection Lithography

Recently, new resist criteria for low energy electron beam projection lithography (LEEPL) such as bi-layer, chemically amplified and silicon containing resists have been requested. In order to investigate the lithographic characteristics of each system, three chemically amplified resist samples consisting of silsesquioxane base polymer were prepared. It was found using a 50kV direct writing electron beam tool that the resist characteristics at 50nm film thickness indicated unique results compared with that of the 100nm, 150nm and 200nm film thickness in the resist screening. The screened resists presented around 80nm resolution with 180nm pitch in LEEPL imaging. However, the coating defect was detailed as a challenge for imaging ultra thin film resists.