MASS-SPECTROMETRIC STUDY OF THE REACTION OF PHOTOOXIDIZED GAAS WITH GA

The Ga-induced reaction of photo-oxidized GaAs, which is used as a mask material for the in situ selective-area growth of GaAs, has been studied by mass spectrometry. An anomalous behavior of photo-oxidized GaAs was observed by measuring the temperature-programmed desorption after Ga predeposition and the desorption response to pulsed Ga injection onto it. Deposited Ga, less than 3 monolayers, did not directly deoxidize the photo-oxidized GaAs into a volatile product, but, on the contrary, stabilized it. This anomalous behavior was not observed for dark-oxidized GaAs. It is considered that Ga-induced stabilization of the oxide makes the photo-oxidized GaAs more effective as a mask for selective-area growth.