GASB-GROWTH STUDY BY REALTIME CRYSTAL-GROWTH ANALYSIS SYSTEM USING SYNCHROTRON-RADIATION PHOTOELECTRON-SPECTROSCOPY

A system has been developed for realtime crystal-growth analysis by ph otoelectron spectroscopy, using vacuum ultraviolet (VUV) light from sy nchrotron radiation. This system consists of a VUV synchrotron radiati on beamline and growth/analysis apparatus in which photoelectron spect roscopy is performed. A ''non-scanning'' photoelectron spectroscopy me asurement method that uses only electron energy dispersion on a multi- channel detector achieves sub-second resolution. This system was used to monitor the GaSb-growth process by alternately supplying Ga and Sb molecular beams; the changes in the chemical state were analyzed with sub-second resolution. The Ga supply resulted in a Ga-full surface; Ga droplets formed on this surface, in which the Sb atoms remained lying on the Ga layer. The Sb supply did not change the ratio of Ga and Sb atoms at the surface from the initial value. These results show that, exposure to an Sb flux causes a crystal surface to once again become a n Sb-rich surface although Ga droplets were previously formed during e xposure to a Ga flux a GaSb surface was thus successfully grown.