Controlled Etching of InGaAlAs and GaAsSb Using Citric Acid∕Hydrogen Peroxide Mixtures

Abstract

This paper reports a study of the etching properties of citric acid∕hydrogen peroxide solution on InGaAlAs and GaAsSb. All data presented here show a trade-off between etching selectivity and roughness of the etched surfaces. The optimal volume ratio of the etchant is found to be 2:1 yielding, respectively, a selectivity of 33 and a roughness of . An increase of volume ratio beyond the optimal value increases the surface roughness, while a decrease leads to decreasing selectivity. The surfaces etched using optimal volume ratio exhibit a high surface stability even after several days of exposure in air.