Electrical Properties of (1-x)Ta2O5–xTiO2 Crystalline Thin Films Prepared by Metalorganic Decomposition

Polycrystalline (1-x)Ta2O5–xTiO2 thin films were formed on a Si substrate by metalorganic decomposition (MOD) at an annealing temperature of 900°C. Thin films with 0.92Ta2O5–0.08TiO2 (x=0.08) composition exhibited superior insulating properties compared to other compositions. The main reason for the improvement in the insulating properties could be the charge compensation of excess oxygen by the TiO2 additive. The leakage current density was lower than 1×10-9A/cm2 up to an applied electric field of 3 MV/cm. The bulk-limited Poole-Frenkel conduction dominates the current–voltage characteristics. capacitance–voltage characteristics of these films showed good dielectric properties with a maximum dielectric constant of 16 and a charge-storage density of 42.5 fC/µm2 at 3 MV/cm.