A study on the law of oxidation rate in GaAs-based VCSELs

In order to accurately control the oxidation aperture in high power vertical cavity surface emitting lasers (VCSELs), the selective oxidation process is studied with experiments. Selective oxidation experiments are carried out upon the simulate wafer of VCSELs at different temperature. Oxidation products are examined at different oxidation depths of oxidation layer and each component content is analyzed. The results of the experiments are analyzed with the kinetics of thermal diffusion. The analyzed results show that the concentration of oxidant is e exponentially declined with increasing depth of oxidation in high-power VCSELs. The oxidation depth stability and precision can be improved by lowering the oxidation temperature and prolonging the oxidation time.