Characterization of extreme ultraviolet resists with interference lithography

摘要

This paper describes extreme ultraviolet (EUV) resist screening results that have been obtained on an interference printer at the Swiss Light Source. Imaging performance of a variety of chemically amplified resists has been studied. The main focus of the work has been on evaluating ultimate resolution and exposure latitudes of various materials and on improving their process parameters. The chemically amplified resists have also been compared with non-chemically amplified PMMA. The resolution of the latter is clearly superior to that of the chemically amplified materials. Below 40-35 nm half-pitch all chemically amplified materials at best show modulation in resist, a limitation that is attributed to acid diffusion. However, PMMA shows clean profiles on the interference printer down to about 20 nm.