Selective Etching of GaAs for ZnSe Based Surface Emitting Lasers

Abstract
We have demonstrated a selective etch process of removing a GaAs substrate for the fabrication of ZnSe-based surface emitting lasers using the PA etchant ( NH3OH:H2O2:H2O=x:33:10) and employing a spray method. The etch rate of a GaAs substrate was 3.7 µm/min with a preferential etch rate ratio of over 20 against ZnSe layers. The surface of the ZnSSe layer after removal of a substrate was smooth enough to fabricate ZnSe-based surface emitting lasers.