Formation of nanostructure on surface of SiC by laser radiation

Nanohill formations were found on a surface of 6H-SiC by the N₂ laser focused beam. These nanohills are situated along the circular line with diameter smaller than that of the focused laser beam. Results of photoluminescence and studies of friction force microscopy speak in favor of an increase in the nitrogen concentration in the nanohills. The pressure of liquid matter in the subsurface area and the pressure of the laser beam on the surface of the sample are taken into account in explaining this phenomenon. The thresh-old character of the effect, accumulation effect and increase of N band on PL spectra testify to the major role of the thermogradient effect in this phenomenon.