Qh. Xie et Je. Van Nostrand, Line-of-sight mass spectrometric study of As/Sb exchange on Sb-terminated and Ga-terminated GaSb (001) during molecular beam epitaxy, J VAC SCI A, 17(2), 1999, pp. 342-346
Rates and total amounts of the arsenic for antimony exchange reaction on th
e GaSb (001) surface are measured via line-of-sight mass spectrometry durin
g molecular beam epitaxial growth. On the Sb-terminated GaSb (001) surface,
an As for Sb exchange is observed to occur at all levels of incident As-2
flux studied. By contrast, on the surface with one monolayer of Ga, there e
xists a critical As-2 flux below which the As for Sb exchange is suppressed
, and a two-dimensional (2D) surface morphology is maintained. Above the cr
itical As-2 flux, the As for Sb exchange is observed to be linear with incr
easing As-2 flux. Substrate temperatures above 470 degrees C and As-2 fluxe
s greater than 1 x 10(-6) Ton beam flux pressure lead to a drastic increase
in As/Sb exchange accompanied by the occurrence of 3D surface morphology.
As/Sb exchange at the interfaces of InAs/GaSb type-II superlattices leads t
o a reduced average lattice constant of the superlattices and degrades inte
rface quality, as determined by x-ray diffraction. (C) 1999 American Vacuum
Society. [S0734-2101(99)03102-4].