DOI: 10.1051/jp3:1995182
J. Phys. III France 5 (1995) 1145-1160

Chemical Vapor Deposition of Thick Tungsten Coatings: Mass Transport Modelling and Experiments

M. Pons¹, A. Benezech¹, P. Huguet², R. Gaufres², Ph. Diez³ and D. Lafforet<sup>3

1</sup>  Laboratoire Science des Surfaces et Matériaux Carbonés, URA CNRS n°413 - ENSEEG-INPG, BP 75 Domaine Universitaire, 38402 Saint-Martin d'Hères, France
²  Laboratoire de Spectrométrie Moléculaire, USTL - Place Eugène Bataillon, 34095 Montpellier, France
³  COMURHEX, BP 29, 26701 Pierrelatte, France

(Received 6 October 1994, revised 10 April 1995, accepted 16 may 1995)

Abstract
Thick tungsten coatings have been produced by chemical vapor deposition (CVD) from H ₂-WF ₆ at a temperature in the range 773-1073 K under a reduced pressure. The experimental set-up was designed for in situ Raman analysis of the gas phase (temperature and WF ₆ concentration) during the growth of tungsten coatings. A two dimensional mass transport model was proposed. It assumes a simple chemical pathway. Only the H ₂ reduction of WF ₆ on the substrate was taken into account. The major objective of the present paper is to report on (i) the experimental deposition rates and the rate values calculated by the model, (ii) the values of temperature and gas phase composition deduced from Raman spectroscopy measurements and the values of these quantities obtained by numerical calculations. Within the range of process parameters investigated, the predictive capabilities of the numerical modelling are demonstrated; in addition the temperature and WF ₆ partial pressure measurements can be recorded by a Raman equipment during the deposition process.

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