Chemical Interaction of CdTe and CdZnTe with Aqueous Solutions of H2O2-HI-Tartaric Acid

An iodine-based etching system, H2O2-HI-tartaric acid, was tested on CdTe samples with (110), (100), (111)A, and (111)B orientations. The etching rate of CdTe was shown to depend on the sample orientation, ratio of etchant composition components, temperature, and rotation speed of the disc. A study of the chemical composition and structure of the (211)B Cd1-x Zn (x) Te surfaces etched under different conditions was carried out. X-ray photoelectron spectroscopy (XPS) measurements showed that a nearly stoichiometric surface was achieved after heating of the etched surface in vacuum. Reflection high-energy electron diffraction (RHEED) measurements revealed a very good single-crystalline surface layer in samples etched with HI-based solutions as compared with bromine-methanol treatment.