Laser implantation of impurities in cadmium telluride crystals
Abstract
Processes of laser implantation of shallow donors (aluminum and indium) and an acceptor (antimony) in CdTe crystals (n,p∼1015 cm−3) are investigated. Thin dopant films vacuum deposited on the etched surface of the crystals are irradiated by ruby (λ=0.694 μm) and Nd:YAG (λ=1.06 μm) laser pulses (pulse duration 20 ns) over a wide energy interval (0.1–1.8 J/cm2). The irradiated surfaces are studied by x-ray microanalysis, Auger spectroscopy, and the thermopower method. It is it is shown that irradiation by a Nd:YAG laser produces a uniform doping of a subsurface layer of the crystal by aluminum. The implantation of indium leads to the formation of a precipitate. The concentration of implanted impurities reaches 1019–1021 cm−3.