Tertiarybutyldimethylantimony for lnSb Growth

Abstract Trimethylantimony (TMSb) is the standard Sb source for OMVPE growth of Sb-containing materials. However, TMSb pyrolyzes slowly for temperatures below 500°C, limiting its usefulness for low temperature growth. Recently, triisopropylantimony (TIPSb) has successfully been used to grow InSb. This allows the growth of high quality layers at V/III ratios near unity for temperatures as low as 430°C. For lower temperatures, higher V/III ratios are required due to incomplete TIPSb pyrolysis. This causes problems for the small bandgap materials which require growth temperatures lower than 400°C. In this work, tertiarybutyldimethylantimony (TBDMSb) is used, together with trimethylindium (TMIn), for the growth of InSb. The optimum V/III ratio is near unity for growth temperatures from 375 to 450°C. Good surface morphology InSb layers can also be obtained at temperatures as low as 350 and 325°C at moderate V/III ratios of 10 and 17, respectively. Using this new Sb source, the growth temperature can be reduced by more than 100°C as compared to TMSb, and about 50°C as compared to TIPSb. Another advantage of using TBDMSb is that the surface morphology for InSb grown using TBDMSb does not depend on V/III ratio as critically as for InSb grown using TIPSb. Moreover, the growth efficiency is high, on the order of 1 × 10 4 μm/mol, for temperatures higher than 400°C. This indicates that there are minimal parasitic reactions between TMIn and TBDMSb. The electron concentration is near 10 16 cm -3 for growth temperatures of between 450 and 375°C. It increases slightly to ∼ 10 17 cm -3 for T g = 350 and 325°C. The 10 K photoluminescence spectra show well-resolved peaks due to exciton and impurity recombination. Samples grown at temperatures higher than 400°C exhibit higher photoluminescence intensities than those grown at lower temperatures. The results indicate that TBDMSb is an excellent replacement for TMSb and TIPSb for the growth of InSb.