TEM investigation of the differences in ion milling induced damage of Hg1−xCdxTe and CdTe heterojunctions

The lattice defects induced by ion milling at the liquid phase epitaxy (LPE) grown HgCdTe on CdTe heterojunction have been investigated using transmission electron microscopy (TEM). TEM analysis reveals that subjecting both materials to identical milling conditions results in much higher defect densities (2–3 orders of magnitude) in the CdTe than in the HgCdTe (x=0.30). In addition, high resolution lattice images of both regions reveal that the stacking fault widths in the HgCdTe are much narrower than in the CdTe, which implies that the stacking fault energy is much higher in the HgCdTe as compared to the CdTe. These observed phenomena are shown to support the weakness and metallicity of the Hg–Te bond as proposed by theoretical considerations.