In this work, the effect of the reactive ion etching (RIE)-induced p-to-n type conversion process on the transport properties of HgCdTe is investigated. Magnetic-field-dependent differential Hall and resistivity measurements have been performed to determine the n-type doping profile and temperature-dependent transport properties of carriers resulting from the RIE-induced type conversion. The study examined Hg1-xCdxTe with x = 0.23 and x = 0.31 for both vacancy-doped and gold-doped p-type epilayers grown by liquid phase epitaxy (LPE) on lattice-matched CdZnTe, which were partly converted to n-type by a RIE process. Analysis using quantitative mobility spectrum analysis (QMSA) reveals that RIE type conversion results in a damaged surface layer characterized by moderate mobility electrons and a bulk n-type region exhibiting higher electron mobility. The surface and bulk electrons show a distinct temperature dependence. It can be observed that, generally, the concentration and mobility of the surface electrons are similar for all samples studied and are independent of temperature in the measured temperature range. In contrast, the bulk electrons exhibit classical behavior with characteristics that are strongly dependent on temperature and consistent with high-quality HgCdTe material. Differential Hall results indicate that the n-type dopants resulting from the RIE process are distributed into the sample via a diffusion process. The results suggest a p-to-n type conversion mechanism involving neutralization of the p-type dopants and diffusion of extrinsic n-type dopants from the surface.
Nguyen, T., Antoszewski, J., Musca, C., Redfern, D. A., Dell, J., & Faraone, L. (2002). Transport Properties of Reactive-Ion-Etching-Induced p-to-n Type Converted Layers in HgCdTe. Journal of Electronic Materials, 31(7), 652-659. https://doi.org/10.1007/s11664-002-0214-4