Surface morphology of r.f. sputtered bismuth titanate thin films

Bismuth titanate (Bi₄Ti₃O₁₂) thin films were prepared by the r.f. sputtering technique. A bismuth-rich target was used to compensate for the loss of bismuth during deposition. Studies on many films, deposited under various conditions, showed that existence of non-uniform erosion leads to many surface morphological features. This varying surface structure is a consequence of the resputtering process. Because the microstructure has a significant effect on the films electrical/optical response, a knowledge of its dependency on process parameters is an important step towards device development.