Effect of growth conditions on Si doping into InAlAs grown by metal-organic vapor phase epitaxy

Doping characteristics of Si in MOVPE grown In/sub 0.52/Al/sub 0.48/As are investigated under various growth conditions such as V/III ratio and growth temperature. We demonstrate that either high V/III ratios (/spl ges/64) or high growth temperatures (/spl ges/720/spl deg/C) are necessary for obtaining good electrical properties of InAlAs. For a small V/III ratio (=32) and low growth temperatures (/spl les/700/spl deg/C), a large discrepancy is found in Hall carrier concentration (n/sub Hall/), ionized impurity concentration (N/sub C-V/) and Si concentration (N/sub Si/); N/sub C-V/>N/sub Si/>n/sub Hall/, which can be explained by the dual formation of donor-type and acceptor-type deep levels. SIMS results suggest that carbon and oxygen impurities are not the candidates for the deep levels, and intrinsic defects, which are closely related to the growth conditions, seem to be formed.