SITE-SELECTIVE MANIPULATION OF SEMICONDUCTOR SURFACES BY LASER-BEAMS

We review current studies of laser-induced atomic emissions (LIAE) fro m semiconductor surfaces, emphasizing that the phenomena arise from de fect-originated site-selective bond breaking on surfaces. First we bri efly discuss photo-stimulated desorption (PSD) of host atoms from soli d surfaces and show that PSD from semiconductor surfaces should be def ect-related and observed only under intense laser irradiation. We then point out that the laser fluence required for bond breaking depends o n the bond strength of atoms to be emitted; lowest for adatom-type def ects and higher for step-type defects and then for vacancy-type defect s. A strategy for obtaining defect-free surfaces employing LIAE and th e recombination of vacancies with deposited host atoms is suggested an d the problems in achieving the goal of producing defect-free surfaces are discussed.