J. Phys. IV France 11 (2001) Pr3-85-Pr3-91
Thermodynamic and experimental study of low temperature ZrB2 chemical vapor depositionJ.F. Pierson1, T. Belmonte2 and H. Michel2
1 Centre de Recherches sur les Écoulements, les Surfaces et les Transferts, UMR 6000 du CNRS, Pôle Universitaire, BP. 71427, 25211 Montbéliard cedex, France.
2 Laboratoire de Science et Génie des Surfaces, UMR 7570 du CNRS, INPL-EdF, École des Mines, Parc de Saurupt, 54042 Nancy cedex, France
A thermodynamic study of the Zr-B-H-Cl system is realised using a cornputer-aided Gibbs energy minimisation program. Effect of the total pressure and the atomic ratio of hydrogen to chlorine (Hl / Cl) on the CVD deposition diagram is investigated. The total pressure decrease lowers the minimal temperature for ZrB2 deposition. It reaches 780 K at 100 Pa. H / Cl ratio affects the ZrB2 + B codeposition domain area. A CVD deposition diagram at 800 K with isoyield curves is also presented. Zirconium diboride films are elaborated on quartz and Zircaloy-4 substrates using ZrCl4 and BCl3 precursors. Since ZrB2 films cannot be synthesised at temperature lower than 800 K by thermal CVD, an original CVD process enhanced by Ar-BCl3 post-discharge has been developed. At 733 K, films obtained using this process are composed of ZrB2 nanograins embedded in an amorphous solid solution of zirconium and boron oxides.
© EDP Sciences 2001