PECULIARITIES OF BI4TI3O12 FILMS GROWN BY DC MAGNETRON SPUTTERING

The peculiarities of the synthesis and crystallization of complex oxid es (Bi4Ti3O12 as an example) from the decay products in magnetron sput tering are discussed. The processes of complex oxide sputtering by ion bombardment, transfer of the products through the plasma to the subst rate, the surface processes on the substrate and oxidation-reduction p rocesses are considered. The dynamics of the layer formation is invest igated by measuring the spectral line intensities (lambda(Bi) = 472.25 nm and lambda(Ti) = 498.1 nm) of the sputtered atoms at the target su rface. The film deposition mechanism is shown to change with distance between substrate and target. A critical distance of h(crit) = 7 nm is found. At h < h(crit) atoms are deposited, while at h > h(crit) molec ules condense. The degree of crystallization depends on oxygen pressur e. Thermal activation strongly affects the deposition rate. In the cas e of molecular deposition at temperatures of greater-than-or-equal-to 900-degrees-C the high-temperature phase of gamma-Bi2O3 forms along wi th Bi2O3 and TiO2. The dielectric loss tangent of Bi4Ti3O12 films depe nds on the bias potential of the substrate.