Low carbon incorporation in GaAs grown by chemical beam epitaxy using unprecracked arsine, trimethylgallium and triethylgallium

Abstract

GaAs epilayers have been successfully grown by chemical beam epitaxy (CBE) using unprecracked arsine (AsH 3) with trimethylgallium (TMG) or triethylgallium (TEG). In the growth using AsH 3 and TMG, three different regions of growth rates were observed with respect to the growth temperature, which is similar to that observed in the conventional CBE or metalorganic molecular beam epitaxy (MOMBE). The growth rates by AsH 3 and TEG, however, produced an anomalous dependence on the growth temperature revealing two humps. Hall measurement, photoluminescence, and secondary ion mass spectrometry (SIMS) analysis data show that all films are p-type and the carbon concentration is greatly reduced compared to the epilayers grown by CBE which employs TMG and precracked arsine. It was also found that the uptake of carbon impurity is significantly reduced when TMG is replaced with TEG. Our results indicate that surface hydrogen atoms dissociated from arsine play an important role in removing hydrocarbon species from the growth surface.