Luminescent analysis of an impurity in the near‐surface layer of thermally evaporated silicon

Abstract

AbstractA low‐temperature (T = 6 K) photoluminescence of surface silicon layers undergoing thermal evaporation in a high vacuum at 1300 to 1350 °C has been studied. It is found that irrespective of the impurity concentration of the initial samples the bands are observed in the luminescence spectra of the surface region of thermally treated plates, which are due to annihilation of excitons bound with: 1) single non‐ionized boron atoms in substitutional positions of the silicon lattice; 2 ) pairs and clusters of substitutional boron atoms in a layer about 1 μm thick. The processes resulting in the formation of a narrow concentration profile of boron atoms near the surface of a silicon plate are discussed. Boron is accumulated due to a considerable difference (by a factor of about 102) between the rates of evaporation of boron and silicon atoms under non‐steady‐state diffusion.