A technique for the local doping and correction of the conductivity of PbSnTe epitaxial layers via indium diffusion from superficial nanometer-thick films

A technique is described for the local indium doping of epitaxial films of a p-type PbSnTe solid solution to obtain a metal-insulator transition at liquid-helium temperatures. The indium was diffused from the surface of the film, from an In layer several nanometers thick, whereas the shape and size of the doped layer were set by a mask. It is emphasized that the oxide layer should be removed before indium deposition, and that the thickness of the deposited indium layer should be precisely chosen based on the thickness of the PbSnTe film. The results of using this technique for films having different compositions and the results of measurements performed on a planar p-i-p structure are considered.