DECOMPOSITION STUDIES OF TERTIARYBUTYLDIMETHYLANTIMONY

The vapor pressure, decomposition temperature, decomposition products, and decomposition reaction order are reported for a novel organometallic vapor-phase epitaxy (OMVPE) Sb precursor, tertiarybutyldimethylantimony (TBDMSb, C4H9(CH3)2Sb). The TBDMSb vapor pressure is 7.3 Torr at 23-degrees-C. The 50% decomposition temperature is 300-degrees-C for both He and D2 ambients in a flow tube reactor with a residence time of approximately 3.2 sec at 300-degrees-C. The decomposition products are primarily C4H10, C4H8, and TMSb in both ambients. The overall decomposition reaction is first order. The decomposition mechanism is believed to be homolysis followed by recombination and disproportionation reactions for C4H9 and (CH3)2Sb groups. Added trimethylgallium (TMGa) has no measurable effect on either the pyrolysis rate or the products. Apparently, TMGa and TBDMSb do not interact during pyrolysis nor do they form a room temperature adduct. No room temperature adduct between TMGa and TBDMSb was formed. It is believed that TBDMSb is a promising Sb precursor for low temperature OMVPE growth.