Effect of Growth Conditions on Electrical Properties of Si-Doped In_0.52Al_0.48As Grown by Metalorganic Vapor Phase Epitaxy

Abstract

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 (≥64) or high growth temperatures (≥720°C) are necessary for obtaining good InAlAs electrical properties. 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 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.

Study of deep levels in InAlAsSb grown via organometallic vapor phase epitaxy

“…A deep-level �0.6 eV below the conduction band has been typically observed in InAIAs [13][14][15]. There is evidence that this defect is caused by oxygen contamination.…”

“…Furthermore, Goto et. al found that the trap concentrations they observed for 0.45 eV had no correlation with oxygen contamination [15]. Instead, the researchers found that increasing the growth temperature of their samples was the key to lowering the trap density, a process which they hypothesized prevented the fonnation of aluminum anti-sites.…”