Remote hydrogen plasma chemical vapor deposition from alkylsilane and alkylcarbosilane single-sources: Mechanism of the process and properties of resulting silicon-carbon deposits

Abstract

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 a remote hydrogen plasma chemical vapor deposition (RHP-CVD). The compounds containing only the Si-C and C-H bonds in the molecular skeleton appear to be inactive, while those with the Si-Si or Si-H bonds are capable of the a-Si:C:H film-formation. The reactivity of the compounds capable of forming films is characterized by the RHP-CVD's rate constants. For most of the investigated source compounds RHP-CVD appears 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 RHP-CVD, a mechanism of the initiation step, as well as a nature of resulting film-forming precursor are presented. The effect of substrate temperature on the chemical structure, composition, compositional uniformity, surface morphology, mechanical properties (hardness, total stress) and optical properties (refractive index, optical bandgap) of the a-Si:C:H film is reported.