Effect of growth conditions on electrical properties of Si-doped In0.52Al0.48As grown by metalorganic vapor phase epitaxy

A systematic study of the electrical properties of Si-doped In0.52Al0.48As grown under various metalorganic vapor phase epitaxy (MOVPE) conditions such as V/III ratio and growth temperature is carried out. It is demonstrated that either high V/III ratios (greater than or equal to 64) or high growth temperatures (greater than or equal to 720 degrees C) are necessary for obtaining good InAlAs electrical properties. For a small V/III ratio (=32) and low growth temperatures (less than or equal to 700 degrees C), a large discrepancy is found in Hall carrier concentration (n(Hall)), ionized impurity concentration (Nc-v), and Si concentration (N-Si); Nc-v > N-Si > n(Hall); which can be explained by the dual formation of donor and acceptor deep levels. SIMS results suggest that carbon and oxygen impurities are not candidates for these deep levels, and other origins such as intrinsic defects, which are closely related to growth conditions, are applicable.