Surface damage and removal of Ar⁺ etched InGaAs, n-InP and p-InP

Surface damage on InGaAs, n-InP, and p-InP after Ar⁺ etching is studied, and it is removed by wet etching post treatments. After Ar⁺ etching, the root-mean-square roughness of InGaAs surface is lower, but the roughness of n-InP and p-InP surfaces is significantly higher. The photoluminescence (PL) intensity of Ar⁺-etched InGaAs increases, but those of Ar⁺-etched n-InP and p-InP decreases. X-ray photoelectron spectroscopy (XPS) is used to investigate the atomic concentration of three samples before Ar⁺ etching and after Ar⁺ etching and wet etching post treatments. After Ar⁺ etching, the content of In and Ga at the InGaAs surface increases markedly, and there is generally a preferential loss of P from n-InP and p-InP surfaces. The surface atomic concentration of the samples after wet etching is almost the same as before Ar⁺ etching.