Photodissociation of Trimethylindium and Trimethylgallium on GaAs(100) at 193nm Studied by Angle-Resolved XPS

Abstract

ABSTRACTThe chemisorption and photodecomposition of trimethylindium (TMIn) and trimethylgallium (TMGa) on GaAs(100) surfaces have been studied by angle-resolved X-ray photoelectron spectroscopy. The In-C bond cleavage of the adsorbed TMIn was observed when the substrate temperature was raised from 150 K to 300 K. The dissociation generates methyl radicals that react with the substrate Ga species to form the Ga-C bond. The In-C bond is also dissociated by 193 nm laser irradiation of TMIn adsorbed on the GaAs at 150 K. Irradiation at 351 nm caused no change in the X-ray photoelectron spectra since photodissociation is not due to the photoabsorption of the GaAs substrate but the photodecomposition of the adsorbed species. Similar results are observed for TMGa on a GaAs(100) substrate.