Growth rate reduction in self-limiting growth of doped GaAs by molecular layer epitaxy

Self-limiting growth of GaAs with doping by molecular layer epitaxy (MLE) has been studied using the intermittent supply of TEG, AsH3, and a dopant precursor, Te(C2H5)(2) (diethyl-tellurium: DETe) for n-type growth on GaAs (001). The self-limiting monolayer growth is applicable at 265degreesC, however, the growth rate per cycle of doping decreased and saturated at about 0.4 monolayer with increasing doping concentration. To clarify the mechanism of growth with doping and to solve the problem of the growth rate reduction, a doping cycle followed by several cycles of undoped growth was performed. The growth rate reduction in the TEG-AsH3 system is due to the electrical characteristics of the growing surface, namely, the exchange reaction of TEG is reduced with increasing doping concentration. (C) 2003 Elsevier Ltd. All rights reserved.