Doping of silicon with selenium by diffusion from the gas phase

Selenium-doped silicon single crystals are studied for the case of an impurity introduced by diffusion from the gas phase. Doping is performed in sealed quartz ampules at a temperature of 1240$^\circ$C over the course of 240 h. The dependence of the concentration of the introduced deep donor centers of various types on the diffusant vapor pressure $p_{\mathrm{Se}}$ is examined. It is found that samples with a concentration of atomic Se centers exceeding 10$^{15}$ cm$^{-3}$ can be obtained at comparatively low $p_{\mathrm{Se}}$ (0.02–0.06 atm). In this case, the content of diatomic Se$_2$ complexes is lower by an order of magnitude and more. The results obtained may be of interest for those who study nonlinear optical phenomena involving deep donor centers in silicon.