MECHANISM OF GAAS SELECTIVE GROWTH IN AR+ LASER-ASSISTED METALORGANIC MOLECULAR-BEAM EPITAXY

Ar+laser-assisted epitaxy of GaAs, GaP, and GaAsP is studied. Laser irradiation during growth enhances growth rates of the three kinds of films. Growth rates of the laser-irradiated areas are the same and remain constant in the substrate temperature range 400–550°C, irrespective of the direct or indirect bandgap semiconductors. Laser beams of 500 mW irradiate a quartz ampule filled with triethylgallium molecules, causing white dots to form on the inside walls of the ampule. These results strongly suggest that the mechanism of the growth rate enhancement is photolytic decomposition of triethylgallium adsorbed on the substrate. © 1990 IOP Publishing Ltd.