LASER-BEAM INTERACTION WITH DEFECTS ON SEMICONDUCTOR SURFACES - AN APPROACH TO GENERATION OF DEFECT-FREE SURFACES

Current studies of laser-induced emissions of semiconductor atoms from semiconductor surfaces, originating from electronic bond breaking, ar e reviewed. Electronic excitation in solids can lead to atomic emissio ns by breaking the bonds of the surface atoms. For semiconductor surfa ces, this process requires multiple excitations and is defect related. Experimental results of atomic emissions induced by nanosecond laser pulses on Si, GaAs, and GaP surfaces show that the emission originates from surface defects, and that the yield is a superlinear function of the laser fluence. Excitation spectra of the yield confirm that emiss ion originates from bond breaking. Related phenomena, including laser- induced dry etching and laser ablation, are also discussed in the cont ext of bond breaking. We conclude that laser-induced electronic bond b reaking may be used to produce defect-free surfaces.