PYROLYSIS OF TERTIARYBUTYLPHOSPHINE AT LOW-PRESSURE

The pyrolysis of tertiarybutylphosphine (TBP) has been studied in the low pressure conditions used for chemical beam epitaxy (CBE). The pyro lysis studies were carried out in low pressure reactors of two differe nt configurations, one of which is a cracker cell designed for use in a CBE system. The reaction products were studied using a quadrupole ma ss spectrometer. The products observed are accounted for by a reaction mechanism involving homolysis of the parent TBP molecule to produce P H2 and C4H9 radicals. These undergo subsequent reactions to form the s table products C4H8, PH3, and H-2, with smaller amounts of P and P-2 b eing produced. The production of the sub-hydride PH2 using this cracke r cell design indicates that the use of partially cracked TBP may be a promising technique for reducing the amount of carbon incorporated in to the growing epitaxial layer.