Reaction of hydrogen peroxide with organosilanes under chemical vapour deposition conditions

When a stream of vapour at low pressure which contained a mixture of H2O2 with an organosilane, RSiH3 (R = alkyl or alkenyl), impinged on a silicon wafer, deposition of oxide films of nominal composition RxSiO(2–0.5x), where x = ≤0.17, was observed. The reactions which accompanied oxide film formation liberated a range of volatile organic compounds consistent with release of R˙ radicals in a novel cleavage of Si–C bonds. No oxidation was detected for silanes containing C3 or higher alkyl groups or C5 or higher alkenyl groups. Possible mechanisms for the Si–C bond cleavage reaction are discussed, with energetic rearrangement of radical intermediates of type Si(H)(R)(OOH)˙ being favoured.