Electronic Resource
[S.l.]
:
American Institute of Physics (AIP)
Journal of Applied Physics
88 (2000), S. 4056-4060
ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Because of well-known surface segregation effects in molecular beam epitaxy growth, Si dopant atoms deposited as thin layers in AlxGa1−xAs typically become distributed over many atomic layers. We have measured the Si depth distributions in (100) and (311)A samples grown at temperatures between 420 and 655 °C, with Al fraction x=0, 0.1, and 0.32. The surface migration decay length Λ for a Si atom on a growing (100) surface is strongly temperature dependent but nearly independent of x, with Λ(approximate)8 nm at 655 °C. The x=0(100) measurements show evidence for a minimum value Λ(approximate)0.6 nm at low temperatures and a maximum value Λ(approximate)8.5 nm at high temperatures. The data are in accord with a thermally activated surface segregation process with activation energy (1.8±0.4) eV acting in parallel with a temperature independent surface segregation mechanism. The (311)A surface shows Λ=(3.3±0.1) nm virtually independent of temperature for x=0. The Si decay length for the (311)A surface strongly increases with x, and for x=0.32 there is no significant difference in Λ for the (100) and (311)A surfaces. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1308073
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