Defect profiles in graded band-gap layers of P-HgCdTe heteroepitaxial structures under ion-beam etching

Abstract

The results of investigations into spatial distribution of donors in p-HgCdTe graded band-gap layers with various composition profiles in the near-surface layer upon ion-beam etching are reported. It is found that the depth of the resulting n + -layer is weakly dependent on the conditions of ion-beam etching and composition of material of the surface and is about 0.5-1 μm. The electron density in the n + -layer on the surface is observed to increase with time of beam etching. It is shown that the conditions of ion-beam etching and the composition of the near-surface region significantly affect only the depth of the foregoing layer with low electron density. Analysis of experimental data shows that the process of ion-bean etching in p-HgCdTe heteroepitaxial structures with a composition gradient in the near-surface region is different from etching in HgCdTe homogeneous epitaxial structures and crystals.