OPTICAL-EMISSION SPECTROSCOPY AS THE MONITORING TOOL IN ECR-MBE GROWTH OF GAN

We demonstrated an observation of excited gallium (Ga) emission by op tical emission spectroscopy (OES) during GaN growth. It was also demon strated that crystal structure of GaN could be controlled by changing bias conditions during electron-cyclotron-resonance plasma-excited mol ecular beam epitaxy (ECR-MBE). Change of GaN crystal structure from he xagonal to cubic (c-) by applied positive bias voltage to the substrat e was observed for the first time. Growth of c-GaN and decrease in Ga emission intensity in deeper positive bias conditions were successful ly explained by suppression of Ga desorption. From these observations, OES is demonstrated to be useful as the monitoring tool in ECR plasma -excited MBE. (C) 1998 Elsevier Science B.V. All rights reserved.