Structural and electrical properties of CaCu₃Ti₄O₁₂ films by room temperature sputtering and rapid thermal annealing process

CaCu₃Ti₄O₁₂ films deposited on Pt/Ti/SiO₂/Si substrates at room temperature by radio frequency magnetron sputtering were annealed with a rapid thermal annealing process at various temperatures and in various atmospheres. X-ray diffraction patterns and scanning electron microscope images demonstrated that the crystalline structures and surface morphologies of CaCu₃Ti₄O₁₂ films were sensitive to the annealing temperature and ambient atmosphere. The polycrystalline CaCu₃Ti₄O₁₂ films could be obtained when the annealing temperature was 700°C in air, and the grain size increased significantly with the annealing temperature in O₂. The 0.8-μm CaCu₃Ti₄O₁₂ film that was deposited at room temperature for 2 h and then annealed at 700°C in O₂ exhibited a high dielectric constant of 410, a dielectric loss of 0.17 (at 10 kHz) and a leakage current density of 1.28×10-5 A/cm² (at 25 kV/cm).