Effect of the chemical structure of silyl derivatives of unsymmetrical dimethylhydrazine on the composition and structure of silicon carbonitride films: Theoretical and experimental studies

• Published in: Inorganic materials Vol. 43; no. 4; pp. 373 - 378
• Main Authors: Smirnova, T. P., Shainyan, B. A., Borisov, V. O., Rakhlin, V. I.
• Format: Journal Article
• Language: English
• Published: 01.04.2007
• ISSN: 0020-1685; 1608-3172
• DOI: 10.1134/S0020168507040085

Quantum-chemical calculations are used to analyze the homolytic decomposition of 1,1-dimethyl-2-(dimethylhydrazino)silane (DMDMHS) and bis(2,2-dimethylhydrazino)dimethylsilane (bisDMHDMS)-precursors for the growth of silicon carbonitride films. The results indicate that the homolytic decomposition of DMDMHS is a highly endothermic process, whereas bisDMHDMS decomposition is almost thermally neutral, owing to the strong bond in the N2 molecule. This indicates that the probability of the breaking of the Si-N bond and the formation of volatile silanes, free of nitrogen, is higher in bisDMHDMS, and accounts for the absence of Si-C groups in films grown from this precursor at room temperature. The conclusions drawn from quantum-chemical calculations are supported by experimental data on the growth kinetics, chemical structure, and composition of layers grown from DMDMHS and bisDMHDMS.