ABSTRACTIn metal organic chemical vapor deposition (MOCVD), the most commonly used sources are the trimethyls of Al, Ga, In, and Sb, and PH3 and ASH3. New organometallic sources are being developed as the understanding of the deposition process improvesand allows for the determination of the effects of source type and growth condition on the properties of the grown films. These new sources are safer and allow for the growth of higher purity materials using more favorable growth conditions. InSb and AlSb prepared using these trimethyl-sources are not of high enough quality to be used in many current device applications. Alternate organometallic Sb sources are being investigated to improve the materials characteristics of InSb grown by MOCVD.InSb grown using trimethylindium (TMIn) and trimethylantimony (TMSb) or triethylantimony (TESb) yielded similar quality materials under similar growth conditions. InSb grown using triethylindium (TEIn) and TESb under similar growth conditions yielded very poor quality n-type material. Three new organometallic Sb sources, triisopropylantimony (TIPSb), tris(dimethylamino)antimony (TDMASb), and tertiarybutyldimethylantimony (TBDMSb) are being investigated. The growth of InSb using TIPSb, TDMASb, or TBDMSb and TMIn was investigated over a temperature range of 350 to 475 °C. InSb grown from TDMASb had similar properties to InSb grown from TMIn and TMSbwhen using a similar temperature and V/III ratio range. The growth rates of InSb using TMIn and either TIPSb or TBDMSb at temperatures <= 425 °C were proportional to both the TMIn flow rate and the temperature. The surface morphology of InSb grown using eitherTIPSb or TBDMSb was very rough for growth temperatures <=425 °C. This may be due to the complex decomposition mechanisms involved and the presence of methyl groups on the surface. The InSb with the highest mobility was grown at 400 °C and a V/III ratioof 3 using TIPSb. It was n-type with a carrier concentration of 2.5 × 1015 cm−3 and a mobility of 78,160 cm2/Vs at 77 K. Both n- and p-type InSb were grown using TBDMSb with mobilities up to 67,530 and 7773 cm2/Vs, respectively at 77 K. The mobility for InSb using either TIPSb or TBDMSb was optimized by going to lower temperatures, pressures and V/III ratios. The opposite was truefor surface morphology which improved with higher temperature, pressure, and V/III ratio. The growth of high mobility InSb with smooth surfaces at T<=425 °C was not achieved with TIPSb or TBDMSb and TMIn under the conditions investigated in this work.
Quantum Dots and Nanowires Grown by Metal–Organic Chemical Vapor Deposition for Optoelectronic Device Applications
