Mechanism of the Initiation Step in Atomic Hydrogen-Induced CVD of Amorphous Hydrogenated Silicon–Carbon Films from Single-Source Precursors

A number of alkylsilanes and alkylcarbosilanes of widely different molecular structure are characterized in terms of their ability to form amorphous hydrogenated silicon–carbon (a-Si:C:H) films in atomic hydrogen-induced chemical vapor deposition (AHCVD). The compounds containing only Si–C and C–H bonds in the molecular skeleton appear to be inactive, while those with Si–Si or Si–H bonds are capable of a-Si:C:H film formation. The reactivity of the latter group of compounds is characterized by determining the AHCVD′s rate constants. For most of the investigated source compounds AHCVD was found to be a non-thermally activated process. Based upon the values of the rate constant and the identified low-molecular-weight and oligomeric products of AHCVD, a mechanism of the initiation step, as well as the nature of resulting film-forming precursor are proposed.