Plasma Deposition and Properties of Silicon Carbonitride Films

Abstract

A variety of advanced analytical techniques were used to characterize silicon carbonitride films grown from new volatile nitrogen-rich silyl derivatives of asymmetrical dimethylhydrazine: (CH3)2HSiNHN(CH3)2 (DMDMSH) and Me2Si(NHNMe2)2 (bisDMHDMS). The results demonstrate that the films contain only Si-C, Si-N, and C(sp3)-N bonds, in relative amounts that depend on the molecular structure of the precursor and deposition conditions. The Si-C/[Si-N + C(sp3)-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(sp3)-N bonds, characteristic of superhard materials, and that the films have a complex, framework structure, rather than being a mixture of Si3N4, SiC, and C3N4. 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.