A variety of advanced analytical techniques were used to characterize silicon carbonitride films grown from new volatile nitrogen-rich silyl derivatives of asymmetrical dimethylhydrazine: (CH 3 ) 2 HSiNHN(CH 3 ) 2 (DMDMSH) and Me 2 Si(NHNMe 2 ) 2 (bisDMHDMS). The results demonstrate that the films contain only Si-C, Si-N, and C( sp 3 )-N bonds, in relative amounts that depend on the molecular structure of the precursor and deposition conditions. The Si-C/[Si-N + C( sp 3 )-N] ratio is considerably larger in the films grown from DMDMSH. The data obtained by a variety of spectroscopic techniques provide solid evidence that some of the films contain C( sp 3 )-N bonds, characteristic of superhard materials, and that the films have a complex, framework structure, rather than being a mixture of Si 3 N 4 , SiC, and C 3 N 4 . The structure of the films depends on the N : Si ratio in the precursor: at N : Si = 2, the films are amorphous and contain nanocrystalline inclusions with a tetragonal structure; at N : Si = 4, the films are purely amorphous. The ability to control the chemical composition and structure of deposits allowed us to produce films with various physicochemical and electrical properties.