J. Phys. III France
Volume 4, Numéro 12, December 1994
Page(s) 2521 - 2529
DOI: 10.1051/jp3:1994295
J. Phys. III France 4 (1994) 2521-2529

Peculiarities of Bi 4Ti 3O 12 films grown by DC magnetron sputtering

A. A. Agasiev, V. I. Orbukh and M. Z. Mamedov

Baku State University, Baku 370145, Azerbaijan Republic

(Received 20 September 1993, revised 21 July 1994, accepted 13 September 1994)

The peculiarities of the synthesis and crystallization of complex oxides (B 4Ti 3O 12 as an example) from the decay products in magnetron sputtering are discussed. The processes of complex oxide sputtering by ion bombardment, transfer of the products through the plasma to the substrate, the surface processes on the substrate and oxidation-reduction processes are considered. The dynamics of the layer formation is investigated by measuring the spectral line intensities ( $\lambda_{\rm Bi} = 472.25$ nm and $\lambda_{\rm Ti} = 498.1$ nm) of the sputtered atoms at the target surface. The film deposition mechanism is shown to change with distance between substrate and target. A critical distance of $h_{\rm crit} = 7$ nm is found. At $h < h_{\rm crit}$ atoms are deposited, while at $h > h_{\rm crit}$ molecules condense. The degree of crystallization depends on oxygen pressure. Thermal activation strongly affects the deposition rate. In the case of molecular deposition at temperatures of $\geqslant 900~^\circ$C the high-temperature phase of $\gamma$-Bi 2O 3 forms along with Bi 2O 3 and TiO 2. The dielectric loss tangent of Bi 4Ti 3O 12 films depends on the bias potential of the substrate.

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