Laser implantation of impurities in cadmium telluride crystals

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. Pis’ma Zh. Tekh. Fiz. 24, 1–6 (June 12, 1998)