GROWTH, DOPING, AND ETCHING OF GAAS AND INGAAS USING TRIS-DIMETHYLAMINOARSENIC

Growth, doping, and in situ etching of GaAs using cracked and uncracke d tris-dimethylaminoarsenic (TDMAAs) in chemical beam epitaxy (CBE) ha ve been studied. A reflection high-energy electron diffraction study i ndicates that the complete decomposition of TDMAAs occurs below 370 de grees C. Possible TDMAAs decomposition pathways, which are consistent with experimental data, are presented. The carbon level in undoped GaA s films and the hole concentration in carbon-doped GaAs films using un cracked TDMAAs are much lower than those using cracked TDMAAs, which m ay be due to atomic hydrogen released from the P-hydride elimination p rocess of uncracked TDMAAs on the GaAs surface. The in situ GaAs etchi ng effect was observed only when the substrate was exposed to uncracke d TDMAAs. Possibly, reactive free radicals generated by uncracked TDMA As on GaAs surfaces are responsible for the etching effect. Surface ro ughness in selective-area growth of GaAs and the poor interfaces in In GaAs/GaAs multiple quantum wells grown by CBE using uncracked TDMAAs m ay result from this etching effect. (C) 1997 American Vacuum Society.