Composition of native oxides and etched surfaces on Hg1−xCdxTe

Hg1−xCdxTe surfaces have been investigated by XPS and ellipsometry after spray etching or polish etching with Br solutions, and after the growth of native oxide films. Etching depletes the surface Cd, and enriches either Hg or Te depending on the etch method. Air‐grown native oxides after etching range up to 25 Å in thickness and are essentially TeO2. This thickness increases with increasing surface Te concentration, which depends on the etch. Native oxides 700 Å thick were grown by anodizing. Results are consistent with CdTeO3 as the major constituent. Stripping anodic oxides with HCl reveals a ∠100‐Å Te‐rich layer between the anodic oxide and substrate. A new way of comparing Hg1−xCdxTe native oxide films, the TeO2 stoichiometry plot, is introduced.