COMPARISON OF ETHYLDIMETHYLINDIUM (EDMIN) AND TRIMETHYLINDIUM (TMIN) FOR GAINAS AND INP GROWTH BY LP-MOVPE

Using TMIn and EDMIn we have carried out a direct comparison of growth behavior of both materials in the standard LP-MOVPE system by growing InP and GaInAs. At identical TMIn and EDMIn partial pressures, the growth rate of InP is nearly 100% higher by using the latter compound, indicating that the growth efficiency is increased due to a lower thermal stability of the EDMIn. High purity InP and GaInAs layers have been obtained for the first time from this material. InP layers grown on 2 inch substrates reproducibly show carrier concentrations around 1014 cm-3 and electron mobilities at 77 K of 109,000 cm2/V&middots. GaInAs layers with homogeneous film composition could be grown on 2 inch InP substrates. X-ray rocking curves show a FWHM of less than 30 arc sec which equals 10-4 lattice constants. Carrier concentrations were in the low 1015 cm-3 range and electron mobilities around 9500 cm2/V&middots at 300 K and 45,000 cm2/V&middots at 77 K reproducibly.