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 w ith an organosilane, RSiH3 (R=alkyl or alkenyl), impinged on a silicon wafe r, deposition of oxide films of nominal composition RxSiO(2-0.5x), where x= less than or equal to 0.17, was observed. The reactions which accompanied o xide film formation liberated a range of volatile organic compounds consist ent with release of R-. radicals in a novel cleavage of Si-C bonds. No oxid ation was detected for silanes containing C-3 or higher alkyl groups or C-5 or higher alkenyl groups. Possible mechanisms for the Si-C bond cleavage r eaction are discussed, with energetic rearrangement of radical intermediate s of type Si(H)(R)(OOH)(.) being favoured.