In Ukrainian

Abstract

The laser-stimulated processes have been studied in semiconductors Si i SiGe after their irradiation as well as influence of these processes on the optical properties of irradiated crystals. The results are shown of optical reflection spectra of n-Si(100) single crystals in the range 0.2–1.7 microns before and after laser irradiation in the energy interval 66–108 mJ/cm 2 and reflection and transmission spectra of Ge 1-х Si x (х = 0.85) solid solutions before and after laser irradiation in the energy range 46.6–163.5 mJ/cm 2 . The mechanisms of laser irradiation are considered and the depth of formation of shock waves, surface temperature, and the depth of melting Si are calculated as dependent on laser irradiation. An increase of reflectivity of Si single crystals, at definite laser treatment is experimentally shown. This integrated effect is explained by differences in optical properties of the surface layer and bulk of material depending on laser irradiation. The study has indicated that in the fundamental optical transition of Ge 1-х Si x (х = 0.85) solid solutions the reflecting capability decreases and transmission increases with the energy of laser radiation. Thus, during the laser irradiation laser-stimulated structural changes in the surface layer of crystal take place, where the complex refractive index differs from that of the bulk material, resulting in increased reflectivity of crystals at detinite laser treatment.