Implementation of slow and smooth etching of GaN by inductively coupled plasma * * Project supported by the National Key R&D Program of China (No. 2017YFB0403001) and the National Natural Sciences Foundation of China (No. 61404134).

Abstract

Slow and smooth etching of gallium nitride (GaN) by BCl3/Cl2-based inductively coupled plasma (ICP) is investigated in this paper. The effects of etch parameters, including ICP power, radio frequency (RF) power, the flow rate of Cl2 and BCl3, on GaN etch rate and etch surface roughness RMS are discussed. A new model is suggested to explain the impact mechanism of the BCl3 flow rate on etch surface roughness. An optimized etch result of a slow and smooth etch surface was obtained; the etch rate and RMS were 0.36 Å/s and 0.9 nm, respectively.