The Experimental Proof of Non - Thermal Nature of the Mechanism of Pulse-Photon Annealing in Semiconductor Materials

Nanosecond laser annealing of GaAs amorphized with B+ ions implantation was investigated. The recrystallization process observed in the experiment does not depend on the initial temperature of the samples (77K or 300K) and can be additive; the efficiency of laser annealing (LA) is determined by the light generated nonequilibrium charge carriers (NCC) rather than by crystal heating; the results of the experiments cannot be explained by the purely thermal mechanism of LA. The hypotheses for the low-temperature LA of semiconductors based on the concept of the change in the quantum state of valence electrons affecting a chemical bond are proposed. If the power of LA ensures light generation of antibonding quasiparticles with a concentration of n_cr in the thickness equal to or greater than the amorphous (defective) layer, melting occurs with further epitaxial growth on the substrate, which agrees well with the results of the experiment where the concentration of light generated NCC was Δn≈ 4·5 10¹⁹cm^-3. (paper)