PROPERITES OF HYDROGENATED AMORPHOUS SILICON CARBIDE FILMS IRRADIATED BY EXCIMER PULSE LASER

A series of hydrogenated amorphous silicon carbide film (a-SiC:H) were prepared by rf plasma-enhanced chemical vapor deposition method. The optical band gap(E^opt_g) of the films can be extended to 2.6eV. The as-deposited alma were then irradiated by a KrF excimer laser. During the irradiation process, hydrogen escaped out of the films, and the structure of the films was changed from an amorphous phase to mixed phases of nanocrystallites of silicon and amorphous silicon carbide. The room-temperature dark conductivity of the laser irradiated films is 6-7 orders of magnitude larger than that of the as-deposited films, which was attributed to the modification of the conductivity mechanism resulting from the structural change.