Lattice-matched growth of InPSb on InAs by low-pressure plasma MOVPE

Abstract

This contribution reports on results of the growth of InAs and InPSb in low-pressure (20 hPa) plasma MOVPE. Our basic aim was to study the effect of deposition temperature, vapor phase composition and precracking the group V molecules on the growth kinetics and material quality. For InAs growth (TMIn, AsH 3) on InAs substrates, material with excellent morphology was achieved in the temperature region of 670 to 770 K (best electrical and morphological quality on SI GaAs at T = 670 K: μ 300K = 19,000 cm 2/V⋯s, n 300K = 10 17 cm -3). AsH 3 precracking did not lead to a further improvement of layer quality. For the epitaxy of InPSb (TMIn, PH 3, TESb) the relative rates of incorporation of P and Sb into the solid are of major interest. Preliminary studies of the growth of InP 1− x Sb x ( x < 0.1) (with TESb plasma, PH 3 plasma) on InP were performed in order to obtain the vapor-solid distribution relation for the group V elements P and Sb under our growth conditions. For the lattice-matched growth of InP 0.69Sb 0.31 on InAs, a substantial decrease of the overall PH 3 consumption by a factor of 13 with PH 3 plasma was noticed. Due to this fact we observed a higher growth efficiency, probably caused by the suppression of prereactions. Layers with electrical properties (on SI InP: μ 300 K = 3500 cm 2/ V· s, n 300 K = 3 × 10 16 cm −3) comparable to those reported in the literature were obtained with and without plasma. In general, the plasma approach leads to an efficient, easily controllable and reproducible process for the lattice-matched growth of InPSb on InAs.