THE REACTIVITY AND MOLECULAR SIZE OF FILM PRECURSORS DURING CHEMICAL VAPOR DEPOSITION OF WSix

Y. SHIMOGAKI; T. SAITO; F. TADOKORO; H. KOMIYAMA

doi:doi:10.1051/jp4:1991211

Numéro		J. Phys. IV France Volume 02, Numéro C2, Septembre 1991 Proceedings of the Eighth European Conference on Chemical Vapour Deposition / Actes de la 8ème Confèrence Européenne sur les Dépôts Chimiques en Phase Gazeuse


Page(s)		C2-95 - C2-102
DOI		https://doi.org/10.1051/jp4:1991211

Proceedings of the Eighth European Conference on Chemical Vapour Deposition / Actes de la 8ème Confèrence Européenne sur les Dépôts Chimiques en Phase Gazeuse

J. Phys. IV France 02 (1991) C2-95-C2-102
DOI: 10.1051/jp4:1991211

THE REACTIVITY AND MOLECULAR SIZE OF FILM PRECURSORS DURING CHEMICAL VAPOR DEPOSITION OF WSi_x

Y. SHIMOGAKI, T. SAITO, F. TADOKORO and H. KOMIYAMA

Department of Chemical Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan

Abstract
A kinetic study of chemical vapor deposition of tungsten silicide films was made, focusing on the reactivity and molecular size of film precursors. Tungsten silicide (WSi_x) films were deposited by low pressure CVD from SiH₄and WF₆. The molecular size of the film precursor was calculated to fit to the diffusion coefficient obtained from the deposition rate profile in a tubular reactor. Typically the size was 5~6Å, which is close to the size of the WF₆ molecule. The sticking probability of the film precursor was also examined by observing step coverage in a micron size trench. The sticking probability was about 0.5 at 270~360°C and dependent only slightly on temperature. The partial pressure ratio of SiH₄ to WF₆ was varied from 5 to 100, but the sticking probability did not change and the step coverage remained poor. Some modifications of reaction system would be required to improve the step coverage.