Reaction of hydrogen peroxide with organosilanes under chemical vapour deposition conditions

Abstract

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 R_xSiO_(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.