Study Of The Etching Technology For GaSb-based Laser

After a brief introduction for the development of GaSb-based laser and its device technology, this dissertation gives exhaustive analysis and discussion on present issues of the etching process for GaSb. There are two main parts:one is a study for the chemical mesa etching for GaSb, and the other is the CMP technology for GaSb.In the first part, there are some improvements for the present chemical etching methods for GaSb. We used hydrochloric acid and phosphoric acid systems separately to investigate the effects of mesa etching, and find that both of HC1/H2O2/CH3COOH and H3PO4/H2O2/C4H6O6had good results,such as anisotropy、bluff mesa and controllable etching rates. Then we adjust the components of the phosphoric acid system and finally got a almost perfect result, which has good etching morphology and low longitudinal etching as well as low surface roughness.Considering the working principle and parameter characteristics of Chemical Mechanical Polishing, the second part is an experimental research on several factors of the CMP for GaSb. It is found that CMP is much better than the other two polishing methods, and the results are correlated to the polishing pressure. Using the acidic and alkaline polishing solution to compare the results, we find that the former is slightly better than the latter. Then we try to add the non-ionic surfactant into the latter solution, and get a desired result.