GROWTH OF INP USING TBP AND DTBP IN METALORGANIC MOLECULAR-BEAM EPITAXY

The growth of high purity InP layers using trimethylindium (TMIn) and different commercial tertiarybutylphosphine (TBP) batches as well as d itertiarybutylphosphine (DTBP) as a new phosphorous precursor was stud ied in a production type metalorganic molecular beam epitaxy (MOMBE) g rowth chamber. The cracking behaviour of TBP was investigated by mass spectrometry. Increasing the beam equivalent pressure from 10(-6) Torr to growth relevant pressures in the 10(-5) Torr range, a transition o f the pyrolysis regime was observed, accompanied with a reduced H-2 P-2 production and a strong formation of the hydride PH3 and dihydride P2H4. This behaviour depends on the conditions on the cracker surface and indicates that the decomposition of TBP occurs by a radical forma tion process. At 77 K the deposited InP layers exhibited Hall mobiliti es better than 100000 cm(2)/V s for the use of three TBP batches from two different suppliers with a best value of 167000 cm(2)/V s at n = 1 .4 x 10(14) cm(-3). The linewidth of the donor bound exciton in the 1. 8 K photoluminescence spectrum of the sample with the highest electron mobility was about 0.09 meV. The first use of DTBP in MOMBE for the g rowth of high purity InP was also encouraging. The best value of the H all mobility at 77 K was 77300 cm(2)/V s with n = 5.1 x 10(14) cm(-3). (C) 1998 Elsevier Science B.V. All rights reserved.