Effects of hydrogen on doping of GaInNAs grown by gas-source molecular beam epitaxy

In this article, we investigate the effects of hydrogen (H) on doping of GaInNAs grown by gas-source molecular beam epitaxy with a rf plasma nitrogen radical beam source. Incorporating nitrogen (N) into p-Ga0.892In0.018As reduces strain and improves thermal stability. With increasing N concentration, more H, from thermally cracked AsH3, is incorporated alongside N into GaInAs. H has two effects on GaInNAs: acting as an isolated donor and passivating shallow dopants by forming complexes. With increasing N concentration, the free carrier concentration in the as-grown highly Be-doped Ga0.892In0.108NxAs1-x is decreased mainly due to H passivation. Rapid thermal annealing (RTA) increases free carrier concentration due to a reduced I-I level. The as-grown undoped Ga0.924In0.076N0.030As0.970,, sample should be p type without I-I since N introduces a localized acceptor-like level. Our as-grown undoped sample in n-type 6.9 x 10(15) cm(-3) due to charge compensation with H donors. After 700 degrees C RTA, the film becomes p-type 5.7 X 10(16) cm(-3) due to the reduced H donors. For highly Si-doped GaInNAs (similar to 1 x 10(18) cm(-3)), H mainly passivates the dopants, so the free carrier concentration is increased after RTA. (C) 2000 American Vacuum Society. [S0734-211X(00)02603-2].