THE CHEMICAL ETCHING OF II-VI/GAAS HETEROSTRUCTURES IN AQUEOUS L-KL-HBR SOLUTIONS

The etching characteristics of CdTe, HgTe, Hg0.6Cd0.4Te, and a CdTe/HgTe multilayered structure in aqueous I:KI:HBr solutions have been studied using films grown by metal-organic chemical vapor deposition on 2° misoriented (100) GaAs. The dissolution rate of the films was found to be linearly dependent on the [I:KI] ω/ω ratio of the etchant, indicative of a kinetically controlled process. In terms of the mesa etching of II-VI heterostructures, the optimum range of solution composition was [I:KI] ω/ω <0.25, allowing the definition of structures with minimum dimensions approaching 1 µm. Quantitative analyses of the etched films by XPS have compared the effects of different [I:KI] ω/ω ratios on the formation of non-stoichiometric surface layers. © 1990, The Electrochemical Society, Inc. All rights reserved.