Research Of Gallium Arsenide Polishing Based On Motion Coupling Confined Etchant Layer Technique

With the development of optical manufacturing technology and microelectronic technology, applications requires less surface damage and material defects. For example, in order to ensure the performance of GaAs material through epitaxial growth or ion implantation, the surface lattice should be intact, while the residual stress and damage are as less as possible. Currently, polishing process technology often require complex processes to meet these requirements. So exploring novel method for low stress, noncontact polishing is very significant. As a novel distance-sensitive electrochemical micronanofabrication method, Confined Etchant Layer Technique(CELT) can be used for noncontact surface smooth processing. But the processing results are strongly affected by fluid motion.First, the impact of various factors on process performance were analyzed theoretically. Assumptions were made based on the chemical reaction dynamics. And a micro-nano electrochemical processing platform was built to achieve motion coupling CELT processing.Then, multivariate experiments were designed to study the coupling effect among feeding velocity, the working distance(between the electrode and the substrate), the processing time and the solution ratio. Three sets of experiments were conduct using central composite design method. Response surface methodology were used to analyzing the experiment parameters’ influence on the process performance. Surface topography were characterized using optical microscopy and atomic force microscopy measurement.Furthermore, a transient model was established by means of multi-physics finite element analysis. Transportation of solutes in flow field and etching process can be traced. Consistency between the simulation and experimental results was well achieved.This research provides basis for the parameter optimization in the next step, and pushes the research in CELT polishing method one step further. In addition, the results of mass transfer behavior in flow field provide references for other electrochemical machining process.