Positron annihilation spectroscopy of laser-irradiated 4H-SiC

Slow positron implantation spectroscopy has been applied to the study of samples of 4H-SiC irradiated by excimer lasers at different wavelengths and fluences. Measurements suggest that irradiation by light of wavelength 193 nm leads to amorphisation of the material, whereas irradiation by 308 nm wavelength light at fluences above 1300 mJ cmy2 creates subsurface damage consistent with the formation of vacancy agglomerates. q1999 Elsevier Science B.V. All rights reserved.