M. Danek et al., GAS-PHASE PYROLYSIS OF TERT-BUTYL(ALLYL) SELENIUM, A NEW PRECURSOR FOR ORGANOMETALLIC CHEMICAL-VAPOR-DEPOSITION OF ZNSE, Chemistry of materials, 7(4), 1995, pp. 731-737
The gas-phase pyrolysis mechanism of tert-butyl(allyl)selenium (tBASe)
, a new organometallic chemical vapor deposition (OMCVD) precursor for
ZnSe, was probed under reduced pressure flow conditions by molecular
beam mass spectrometry (MBMS). The precursor decomposed in a hydrogen
carrier gas above 180 degrees C to selenium, propene, 2-methylpropene,
2-methylpropane, 1,5-hexadiene, diallylselenium (DASe), and hydrogen
selenide. Pyrolysis in deuterium did not result in any isotope exchang
e between the carrier gas and pyrolysis products. A mechanism involvin
g beta-hydrogen transfer and homolysis of the Se-C bonds as the primar
y decomposition pathways is proposed. Copyrolysis of tBASe with dimeth
ylzinc (DMZn) in hydrogen yielded methane, propene, 2-methylpropene, 1
,5-hexadiene, methyl(allyl)selenium (MASe), and dimethylselenium (DMSe
) as the major volatile products. The underlying mechanism for formati
on of selenium byproducts is described, and the impact of the pyrolysi
s chemistry on growth and carbon incorporation is discussed.