Anodic Dissolution of n-GaP (111) Surface in Aqueous KOH Solutions

The technique of chemical polishing or electropolishing of n-GaP to obtain a flat (111) surface has not fully been developed. We examined the anodic etching behavior of the (111) surface of Te-doped GaP in aqueous KOH solution at room temperature under normal indoor illumination. The (111) surface became smooth microscopically by etching at a voltage above 24 V in 0.1–0.5 kmol/m3 KOH. In addition, we have also demonstrated a novel method for revealing lattice defects in the crystal by anodic etching under specified conditions.