Pyrolysis of diisopropylantimony hydride: a new precursor for organometallic vapor phase epitaxy

The pyrolysis of diisopropylantimony hydride (DIPSbH), (C3H7)2SbH, has been studied in an isothermal flow-tube reactor. The reaction products in H2, D2, and He carrier gases were studied using a time-of-flight mass spectrometer. T50 for this compound (200‡C) is significantly lower than that of other antimony sources, such as trimethylantimony (450‡C). In addition to the hydride, the decomposition of diisopropylantimony deuteride (DIPSbD), (C3H7)2SbD, was studied to provide insight into the pyrolysis mechanism. The rate limiting step was found to be first-order and is believed to be a reductive elimination reaction which produces C3H8 in the case of DIPSbH and C3H7D in the case of DIPSbD. An increase in the ratio of [C3H6] to [C3H8] was observed as the temperature was increased from 200 to 275‡C, indicating that other reactions, possibly Β-hydrogen elimination, are important as well. The reaction rate and the products produced were not affected by changing the carrier gas. The temperature dependence of the vapor pressure was determined and is described by the equation log (P)(Torr) = 7.948-2100/T(l/K).