Etch Characteristics and Mechanism of TiSbTe Thin Films in Inductively-Coupled HBr-He, Ar, N2, O2 Plasma

Abstract

Etch characteristics and mechanisms of TiSbTe thin films in inductively coupled HBr-He, HBr-Ar, HBr-N2, and HBr-O2 plasmas were studied in this paper. The etch rate of TiSbTe thin film was measured as functions of the additive gas fraction for He, Ar, N2 and O2 at a fixed gas pressure (5 mTorr, 1 mTorr = 0.133Pa), input power (700 W), bias power (300 W), and total gas flow rate (200 sccm). The etch rate and surface roughness of TiSbTe thin films showed non-monotonic behaviors as the increasing additive gas fraction in four plasma systems. Meanwhile, different kinds of additive gas resulted in different quantitative correlations between chemical and physical etching pathway, which eventually make difference on the etch rate and surface roughness of TiSbTe thin film. The surface chemical status of each component was also investigated in this study. The good performance of etch rate, surface roughness and low plasma damage suggested that HBr-Ar plasma is the best choice for TiSbTe etching compared with HBr-He, N2 and O2 plasma.