A precursor composition is disclosed for use in the chemical vapor deposition of a material selected from the group consisiting of silicon oxynitride, silicon nitride, and silicon oxide. The composition comprises a hydrazinosilane of the formula: [R.sup.1.sub.2N--NH].sub.nSi(R.sup.2).sub.4-n where each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=1-4.