An abrupt transition to a {111} faceted growth mode is observed in molecula
r-beam-epitaxy growth of dilute GaNxAs1-x (x < 0.05) films on (100) GaAs su
bstrates. The faceted growth mode is favored by high growth temperatures, h
igh nitrogen content, and high arsenic flux. The best electronic quality ma
terial, as measured by low-temperature photoluminescence. was obtained at h
igh growth temperatures and high arsenic flux without exceeding the thresho
ld for facet formation. The nitrogen content was found to be insensitive to
the arsenic flux. (C) 2001 American Vacuum Society.