Etching and smooth processing of GaAs surface based on the confined etchant layer technique

Confined etchant layer technique (CELT) is an effective electrochemical etching method for micro-machining, which can be used to replicate complex three-dimensional microstructures and implement rough surface smooth processing. Through the coupling between electrochemically induced chemical etching processes and mechanical motion, a combination of high machining efficiency, low machining cost and good machining accuracy can be reached. In this paper, a CELT processing platform was established. By combining simulations with experiments, we studied the influence of the solution proportioning on the etching results of GaAs surface and verified the capacity of the CELT technique to achieve smooth processing. It is shown that by taking advantage of CELT, the surface roughness can reach nano-scale.