Features of Pulsed Laser Annealing of BC₃ Films on a Sapphire Substrate

The morphology, chemical composition, microstructure, and electrical properties of BC₃ thin films subjected to melting by a nanosecond laser pulse are investigated. The original films have been created by pulsed laser codeposition of B and C onto a sapphire substrate at 150 and 350°C. Morphological changes in the films depended on their initial structural state. However, a "frozen" structure of both films after irradiation corresponded to the B-saturated graphite-like phase, the local composition of which varied due to the formation of inclusions of amorphous boron carbide. Before and after irradiation, the films exhibited a slightly decreasing dependence of the surface resistance with increasing temperature from 4.2 to 330 K. After laser irradiation, the films resistance has decreased by a factor of ~2.6.