In the preparation of oxide confinement vertical-cavity surface-emitting lasers, selective internal corrosion often occurs when GaAs/AlGaAs is etched, which directly affects the subsequent oxidation process and electrode passivation. To address this problem, the wet and the dry etching processes are thoroughly investigated in this study. Results show that the hollows caused by selective internal corrosion can be effectively eliminated by adjusting the volume ratio of the etching solution and bottom electrode radio frequency (RF) power of the inductively coupled plasma (ICP) etching. We obtain good steepness and smoothness in the wet etching process when the volume ratio of the H3PO4-H2O2-H2O solution is 1:1∶10. In the ICP dry etching process, the dynamic balance of the chemical and physical etching in the chamber is adjusted by changing the RF power of the bottom electrode; the hollow phenomenon is hardly observed, and the sidewall steepness is greater than 80° at a power of 100 W.