Methods for plasma enhanced chemical vapor deposition (PECVD) of silicon carbonitride films are described. A flowable silicon carbonitride film is formed on a substrate surface by exposing the substrate surface to a precursor and a reactant, the precursor having a structure of general formula (I) or general formula (II) wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, and R12 are independently selected from hydrogen (H), substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted vinyl, silane, substituted or unsubstituted amine, or halide; purging the processing chamber of the silicon precursor, and then exposing the substrate to an ammonia plasma.