Sub 30nm Node Contact Hole Patterning Using Immersion Single Exposure with Negative Tone Development

Abstract

Contact hole patterning for 22nm node and beyond has become much more challenging. Since extreme ultraviolet lithography (EUV) is not yet ready, double patterning (DP) technology seems to be the most likely solution to achieve minimum half pitch of 40nm and below using immersion ArF lithography. The negative tone development (NTD) technique having excellent image contrast has received considerable attention as a possible alternative because it doesn't have the cost and throughput concerns that double patterning has. In this paper, we describe simulation and lithographic performance comparing single exposure (SE) negative tone development (NTD) technique with single exposure (SE) positive tone development (PTD) technique in terms of resolution through pitch.