Composition and structure of films deposited from silyl derivatives of asymmetrical dimethylhydrazine

Si-N-C films were produced by remote-plasma chemical vapor deposition using silyl derivatives of asymmetrical dimethylhydrazine as precursors and were characterized by optical spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, and synchrotron x-ray diffraction. The results demonstrate that Si-N and Si-C bonds prevail in the films deposited using excited hydrogen, while the structure of the films deposited using excited helium is dominated by Si-N and C-N bonds. The films contain both amorphous and crystalline silicon carbonitride. The crystalline phase can be indexed in a tetragonal cell with lattice parameters a = 9.6 Angstrom and c = 6.4 Angstrom. The formation of the crystalline phase and the shape of the crystallites are not correlated with the deposition temperature, which gives grounds to believe that the crystallization process may occur in the gas phase or on the film surface as a result of the increase in mechanical stress with increasing film thickness.