Kinetics of the Thermal Desorption of Indium from GaAs(100).

Accurate kinetic parameters for desorption of group-III metals are necessary in modeling of epitaxial deposition of ternary and quaternary III-V films. We report studies of the kinetics of thermal desorption of In from Ga-stabilized GaAs(100) in ultrahigh vacuum. In coverage was monitored by X-ray photoelectron spectroscopy (XPS), while the substrate temperature was accurately measured using infrared laser interferometric thermometry. In was deposited on GaAs by dosing, at room temperature, to saturated monolayer coverage (In ~ 2 x 10 sup (14) cm sup (-2)), with trimethylindium. Subsequent heating to 400C desorbs all hydrocarbon species without affecting In coverage. Further heating leads to first-order desorption of In, as confirmed by exponential decay of In(3d 5/2) XPS signal in isothermal desorption experiments at 473 and 503K.