Influence of Doping Concentration on the Etching Rate of GaAs Studied by Atomic Force Microscopy

Abstract

In this work, the effects of doping concentration on the etching rate of GaAs were investigated. The fabrication of several etching steps on each sample, forming an “etching staircase,” enabled the use of atomic force microscopy for the determination of the etching rate. We have employed a common etching agent and samples in which the only varying parameter was the bulk doping concentration. A strong correlation between etching rate and doping concentration was found, indicated by a decrease in the etching rate as the bulk doping concentration is increased. The experimental results were well accounted for by an oxidation-reduction process, which rules the etching process in the present case.