EFFECT OF HYDROGEN PLASMA PRECLEANING ON THE REMOVAL OF INTERFACIAL AMORPHOUS LAYER IN THE CHEMICAL-VAPOR-DEPOSITION OF MICROCRYSTALLINE SILICON FILMS ON SILICON-OXIDE SURFACE

Microcrystalline silicon(mu c-Si) film deposited on silicon oxide in a remote plasma enhanced chemical vapor deposition (RPECVD) with disila ne (Si2H6) and silicon tetrafluoride (SIF4) has been investigated. It was found that in situ hydrogen plasma cleaning of the substrate prior to deposition is effective to reduce the interfacial amorphous transi tion region. It is believed that hydrogen plasma cleaning generated ad sorption and nucleation sites by breaking weak Si-O and Si-Si bonds an d also removed oxygen/carbon impurity. Surface roughening was observed from the hydrogen plasma precleaning which helped nucleation and crys tallization at the initial stage of the growth. (C) 1996 American Inst itute of Physics.