OMVPE Growth of Epitaxial InSb Thin Films Using a Novel Group V Source Compound

Abstract

ABSTRACTTo date, OMVPE has failed to grow epitaxial InSb at temperatures below about 400 °C. Therefore, we have studied InSb deposition using the novel group V source triisopropylantimony (TIPSb) with trimethylindium (TMIn), comparing this with results in the same reactor using trimethylantimony (TMSb). We have grown InSb on both GaAs and on high-resistivity p-type InSb substrates, exploring the effects of temperature, substrate, V/ill ratio, and thickness on film properties. Our best results with TMSb and TMIn were obtained using a V/ill ratio of 8 and growth temperature of 450 °C. The unintentionally doped films exhibited good crystallinity and were n-type about lx1015 cm-3 down to 5 K, with 77 K mobilities of 90,000 and 253,00°Cm2/V-sec for InSb on GaAs and on InSb, respectively. These results are comparable to the best published MBE data. While InSb films could not be grown well at temperatures below 425 °C using TMSb, specular epilayers were obtained with TIPSb at temperatures as low as 300 °C, though with a low deposition rate. Our best conditions with TIPSb were with a Vill ratio of about 12 and a substrate temperature of 350 °C. The results of variable temperature and variable magnetic field Hall, double crystal x-ray diffractometry, Nomarski microscopy, Auger electron spectroscopy and scanning electron microscopy will be presented.