Chemical etching of InP

Abstract

The chemical etching of InP by iodic acid (HIO/sub 3/) solutions of varying weight percentage has been characterized in detail. The concentration dependence of etch rate of activation energies, and of etch profile has been evaluated. Solutions below 20 wt.% concentration are reaction-rate limited and are found to be useful for InP processing. The chemical state of the surface has been studied by X-ray photoelectron spectroscopy (XPS). These solutions oxidize the surface resulting in the formation of InPO/sub 4/:xH/sub 2/O, which could be useful for Schottky and MIS device applications. The use of a 20 wt.% solution for mesa type etching applications and a 5-10 wt.% solution for cleaning purposes is suggested.<>