Polymeric Resists for X-Ray Lithography

Abstract

It has been demonstrated that high resolution patterns can be delineated in poly (methyl methacrylate) using x‐ray radiation modulated by an absorbing mask. For this technique to be effective, families of both positive and negative x‐ray resists must be available which have properties that allow exploitation of x‐ray lithography. This paper describes the evaluation of several polymeric electron resists for x‐ray resists and demonstrates a good correlation between x‐ray energy absorbed and electron energy absorbed for equivalent degrees of chemical reaction. The incorporation of heavy atoms in the resist to enhance the x‐ray energy absorption and hence increase the material sensitivity has been demonstrated. The effects of a resist's contrast on ultimate pattern resolution and fidelity is discussed in relationship to the x‐ray mask contrast.