Ion milling-assisted study of defect structure of HgCdTe films grown by liquid phase epitaxy

Ion milling, as a tool for “stirring” defects in HgCdTe by injecting high concentration of interstitial mercury atoms, was used for studying films grown by liquid phase epitaxy (LPE) on CdZnTe substrates. The films appeared to have very low residual donor concentration (∼10¹⁴ cm⁻³), yet, similar to the material grown by molecular beam epitaxy, contained Te-related neutral defects, which the milling activated electrically. It is shown that ion milling has a stronger effect on HgCdTe defect structure than thermal treatment, and yet eventually brings the material to an “equilibrium” state with defect concentration lower than that after low-temperature annealing.