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

Doping characteristics of Si in MOVPE grown In_0.52Al _0.48As are investigated under various growth conditions such as V/III ratio and growth temperature. We demonstrate that either high V/III ratios (⩾64) or high growth temperatures (⩾720°C) are necessary for obtaining good electrical properties of InAlAs. For a small V/III ratio (=32) and low growth temperatures (⩽700°C), a large discrepancy is found in Hall carrier concentration (n_Hall ), ionized impurity concentration (N_C-V) and Si concentration (N_Si); N_C-V>N_Si>n _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