Conducting polymers: applications in lithography

Abstract

Electron beam (e-beam) lithography is a direct-write method capable of submicron device fabrication. This paper describes the use of electrically conducting polyanilines as discharge layers for electron beam lithography. The emeraldine oxidation state polyaniline is a soluble material which can be doped by various cationic reagents, most commonly protonic acids, to display conductivity on the order of 10 ohm-1cm-1. The conducting polyanilines are incorporated as thin interlayers (2000 angstrom) in a multilayer resist system consisting of a planarizing underlayer (2.8μm) and the imaging resist (1.2μm) on top. Various acid treated polyanilines eliminate charging during e-beam patterning of the resist, i.e., zero pattern displacements are observed. A minimum conductivity of 10-4ohm-1cm-1 is required of the polyaniline interlayers in order to observe zero pattern displacement.