LEAKAGE CURRENT BEHAVIORS IN RAPID THERMAL ANNEALED BI4TI3O12 THIN-FILMS

Bi4Ti3O12 thin films have been grown on indium-tin-oxide coated glass by pulsed laser deposition. Films are rapidly thermal annealed at 650- degrees-C in three kinds of atmospheres such as O2, N2, and air. The a nnealing atmosphere is found to be an important growth parameter which determines the crystallization, microstructures, and the leakage curr ent behaviors. The film annealed in oxygen has a columnar grain struct ure with an amorphous phase, and its leakage current behavior is in ag reement with the prediction of the space-charge-limited conduction mod el. The film annealed in nitrogen has polycrystalline porous structure ; and its high field conduction is well explained by thermoionic emiss ion model, called the Poole-Frenkel emission. On the other hand, the f ilm annealed in air has both the columnar and porous structures, and i ts electrical behavior shows characteristics of both models.