Junction delineation by anodic oxidation in InSb (As, P)

The rate of anodic oxidation of InSb in KOH has been found to depend on the doping concentration of the semiconductor. The anodization process thus provides a means to delineate junctions in this material and, similarly, in InAs and InP. Anodization patterns have been correlated with the profiles of diffusion by which the junctions are fabricated. Zn- and Cd-diffused junctions in InSb have been studied in some detail; the latter are consistently flatter and have better electrical characteristics. The cause seems to lie in the semiconductor, involving a residual impurity reacting witht he diffusing Zn. Some experiments illustrating selective masking by an oxide layer against diffusions are also described, the masking action against Cd having been found to be more effective. © 1967.