Electrical properties of the anodic oxide-HgZnTe interface

The electrical properties of the anodic oxide- Hgsub0.833Znsub0.167Te interface were studied by means of capacitance-voltage measurements of metal- insulator-semiconductor capacitors. Hgsub0.78Cdsub0.22Te test samples were simultaneously processed for comparison. The fixed insulator charge density was lower in HgZnTe than in HgCdTe, but still large enough to invert the p-type material surface at 0 V. The HgZnTe interface was more stable under thermal treatments than the HgCdTe interface. Hall-effect measurements at variable temperature were used to determine the bulk electrical properties. A two-band model with empirical relations for the energy gap and intrinsic carrier concentration yielded an excellent fit to the experimental data.