Abstract: Ta₂O₅ thin films were deposited by DC reactive magnetron sputtering followed by rapid thermal annealing(RTA). Influence of sputtering pressure and annealing temperature on surface characteristics, microstructure and optical property of Ta₂O₅ thin films were investigated. As-deposited Ta₂O₅ thin films are amorphous. It takes hexagonal structure (δ-Ta₂O₅) after being annealed at 800 ℃. A transition from δ-Ta₂O₅ to orthorhombic structure (L-Ta₂O₅) occurs at 900−1 000 ℃. Surface roughness is decreased after annealing at low temperature. Refractive index and extinction coefficient are decreased when annealing temperature is increased.

Key words: Ta₂O₅ thin films; DC reactive magnetron sputtering; sputtering pressure; rapid thermal annealing(RTA)