ELECTRON BEAM LITHOGRAPHY FOR SUB-100NM DEVICES

Abstract

Electron beam lithography has always been one of the prime techniques to produce very high resolution patterns, especially when photolithography suffers from diffraction effects when it comes to printing sub-100nm features. This project aims at optimizing the E-beam lithography process for sub-100nm resolution, with a focus towards achieving 50 nm patterns using resists namely SAL-601, a chemically amplified negative e-beam resist, Poly Methyl Methacrylate (PMMA), a polymeric positive e-beam resist and evaluate the effects of a chemically amplified positive photo resist UV210 towards electron beam exposure. The thickness, Post Exposure Bake (PEB) temperature and development time have been optimized for the same. In situ monitoring has been carried out using Hitachi Critical Dimension Scanning Electron Microscopy (CDSEM) S9200. SAL 601 has been able to produce 90nm lines. These results would prove very useful for fabricating high performance devices like the FinFET, where the channel length is below 100nm.