TRANSFORMATION OF A SYSTEM OF DEFECTS NEAR THE SURFACES OF CDTE, ZNXCD1-XTE AND CDTE1-XSEX CRYSTALS ETCHED WITH ARGON IONS

Low-temperature photoluminescence, x-ray microanalysis, and secondary-ion mass spectrometry were used in combination with layer-by-layer etching in a study of changes in the impurity-defect composition of p- and n-type CdTe samples and of ZnxCd1-xTe(x less-than-or-equal-to 0.05) and CdTe1-xSex (x less-than-or-equal-to 0.05) solid solutions subjected to argon etching. A new S photoluminescence band was emitted from a thin (approximately 0.1-mum) surface layer as a result of such etching. This band was due to recombination via donor-acceptor pairs containing Li or Cl atoms located in stressed regions near dislocation loops or clusters. The long-range effects of the Ar+ etching were due to thermal heating of the lattice and the associated deviations from stoichiometry, which resulted in changes in the impurity-defect ensemble.