Trimethylgallium dissociative chemisorption on gallium-rich GaAs(100) surfaces

Journal Article · Fri Nov 01 04:00:00 EST 1991 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.577148· OSTI ID:5157882

Creighton, J R ^[1]

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1. Sandia National Laboratories, Albuquerque, New Mexico (USA)

Trimethylgallium (TMGa) chemisorption on the gallium-rich (4{times}6)'' and (1{times}6) GaAs(100) surfaces has been studied with temperature programmed desorption (TPD) and static secondary ion mass spectroscopy (SSIMS). Low coverages of TMGa irreversibly dissociate on GaAs(100) and methyl radicals are the main gas-phase product observed around 700 K during TPD. At higher TMGa coverages some recombinative desorption of molecular TMGa occurs from 250--650 K. On the Ga-rich surface reconstructions the desorbing methyl radicals are kinetically indistinguishable, strongly suggesting that they evolve from a single type of binding site. We believe this binding site corresponds to surface MMGa, which is formed by stepwise methyl group transfer from chemisorbed TMGa to neighboring surface gallium atoms. The presence of MMGa is supported by SSIMS results at {similar to}650 K. Temperature-programmed SSIMS was used to follow the dissociation of adsorbed TMGa from 120 to 700 K.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5157882
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 9:6; ISSN JVTAD; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKYL RADICALS
ARSENIC COMPOUNDS
ARSENIDES
CHEMICAL REACTIONS
CHEMISORPTION
DESORPTION
DISSOCIATION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
MEDIUM TEMPERATURE
METHYL RADICALS
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PNICTIDES
RADICALS
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES