Laser-induced transformation of the microstructure of SiOx, x 1

The chemical composition and the microstructure of glasslike SiO x , x 1, are investigated by means of IR spectroscopy, Raman scattering, and X-ray spectral analysis and diffractometry. These studies revealed a heterophase microstructure of SiO x samples, x 1, consisting of a spatially nonuniform mixture of silica and amorphous, microcrystal, and crystal silicon. The studied samples displayed a photosensitivity in the visible and mid-IR spectral ranges associated with photothermal variations in the microstructure. The photosensitivity of the samples was manifested in the dependence of Raman spectra on the intensity of 514-nm Ar + -laser radiation, amorphization of silicon at laser intensity of ∼4 x 10 7 W/cm 2 , and a higher crystallization degree of irradiated samples. Irradiating samples with CO 2 -laser radiation with an intensity of ∼500 W/cm 2 during ∼5 min in an Ar atmosphere, we melted out drops of crystal silicon with sizes up to ∼1 mm.