WIRE-LIKE INCORPORATION OF DOPANT ATOMS DURING MBE GROWTH ON VICINAL GAAS(001) SURFACES

The ordered incorporation of dopant atoms by combining lattice step gr owth on vicinal GaAs(001) surfaces and Si delta(delta)-doping has been studied by real-time reflection high-energy electron diffraction (RHE ED) measurements. For Si deposition on 2-degrees toward the (111)Ga pl ane misoriented surfaces and 0.4-degrees toward the (11BAR1)As plane m isoriented surfaces it is shown that the Si atoms arrange themselves p referentially along the step edges in a (3 x 2) structure consisting o f an ordered array of Si dimers. For Si concentrations not exceeding s ubstantially the amount expected to be attached at the step edge the G aAs growth can be continued at reduced substrate temperature without a dverse effects on the growth front. By pulsed delta-doping an unusual high concentration of Si atoms can be incorporated as donors on Ga sit es.