Hard and High-Temperature-Resistant Silicon Carbonitride Coatings Based on N-Silyl-Substituted Cyclodisilazane Rings

Abstract

1,3-bis(dimethylsilyl)-2,2,4,4-tetrametyhylcyclodisilazane was used as a single-source precursor for the production of silicon carbonitride (SiCN) thin-film coatings by remote microwave hydrogen plasma chemical vapor deposition (RP-CVD). The effect of the substrate temperature (TS) on the rate and yield of the RP-CVD process, chemical composition, chemical structure, and surface morphology of the resulting film is reported. The temperature dependencies of the thickness-based growth rate and growth yield of the film imply that for the low substrate temperature range (35≤ TS <200°C), film growth is limited by adsorption of film-forming precursors, whereas in the high substrate temperature range (200≤ TS ≤400°C), film growth is independent of the temperature and RP-CVD is a mass-transport limited process. The increase of the substrate temperature from 35 to 400°C causes the elimination of organic moieties from the film and the formation of the Si-C network, which contains incorporated N-silyl-substituted cyclodisilazane molecular skeletons of the precursor linked with the network via the Si-C bonds. The microscopic examination revealed that the films are defect-free materials of excellent morphological homogeneity and exhibit small surface roughness, which vary in a narrow range of values. The SiCN films deposited at various substrate temperatures were characterized in terms of their density, adhesion to a substrate, hardness, elastic modulus, and friction coefficient. The film properties are strongly influenced by the compositional and structural parameters represented, respectively, by the contents of nitrogen and Si-C bonds; the latter described by the relative integrated intensity of the Si-C infrared band. The reasonable relationships between the film properties and the mentioned compositional and structural parameters have been determined. © 2008 The Electrochemical Society.