Nano-Structures Stiction Suppression by Molecular Structure Optimized Surface Energy Reduction Agent

Abstract

Scaling of semiconductor devices has caused nano-structure stiction issues during the drying step of wafer cleaning. We have already proposed a surface modification process to reduce the surface energy, and we have demonstrated this process is more effective for preventing nano-structure stiction than conventional IPA (isopropyl alcohol) drying. In this paper, the proper molecular structure is investigated for surface modification agents. It is important for the suppression of stiction to reduce a surface free energy rather than to increase a water contact angle. We have attained stiction free drying of a high aspect ratio pattern with 15 nm half pitch line and space using agents with shorter alkyl groups.