SiCl4-based reactive ion etching of ZnO and MgxZn1−xO films on r-sapphire substrates

Abstract

SiCl4-based reactive ion etching (RIE) is used to etch MgxZn1−xO (0≤x≤0.3) films grown on r-plane sapphire substrates. The RIE etch rates are investigated as a function of Mg composition, RIE power, and chamber pressure. SiO2 is used as the etching mask to achieve a good etching profile. In comparison with wet chemical etching, the in-plane etching anisotropy of MgxZn1−xO (0≤x≤0.3) films is reduced in RIE. X-ray photoelectron spectroscopy measurements show that there is no Si and Cl contamination detected at the etched surface under the current RIE conditions. The influence of the RIE to the optical properties has been investigated.