Ion beam irradiation of relaxed amorphous silicon-carbide

In-situ transmittance measurements at lambda=633 nm are used during ion irradiation to probe the defect generation in relaxed amorphous silicon carbide (SiC). The optical constants of amorphous SiC are strongly correlated to the thermal history of the material and the transmittance of ion implanted amorphous SiC (unrelaxed amorphous) increases after annealing in the temperature range 100-700 degrees C. The transmittance of annealed amorphous SIC (relaxed) during subsequent implantation decreases and saturates to the value of unrelaxed amorphous. In-situ transmittance measurements allow to follow directly the defect generation and to measure the fluence at which the transmittance saturates (derelaxation fluence). The effect of different ions (He and Ar) on these phenomena is explored. The obtained results are compared and discussed with similar measurements performed on amorphous silicon. (C) 1999 Published by Elsevier Science B.V. All rights reserved.