Performance comparison of metalorganic vapor phase epitaxy grown C-doped GaAs/AlGaAs heterojunction bipolar transistor wafers between AsH 3 and trimethylarsenic for the base layer growth

Abstract

C-doped GaAs layers were grown with AsH 3 and As trimethylarsenic (TMAs) for the As source by a production scale metalorganic vapor phase epitaxy machine. In both cases, highly ( p = (1−4) x 10 19 cm -3) p-type C-doped GaAs layers were grown and no significant difference in their mobilities, carbon activation ratios and electron lifetimes were observed. By means of these methods, GaAs/AlGaAs heterojunction bipolar transistor (HBT) layers were grown and HBT test devices were fabricated. Current gains up to the base layer concentration of 3 x 10 19cm -3 were almost equal for these two methods, but at a concentration of p = 4 x 10 19 cm -3, the current gain of HBT whose base layer was grown with AsH 3 decreased rapidly. On the other hand, a current gain as high as 100 was demonstrated for a HBT whose base layer was grown with TMAs and was 4 x 10 19 cm -3 in concentration.