Temperature-stable dielectrics for TiO2 film prepared by thermal oxidation

Abstract

The thermal oxidation film of titanium has been applied and studied for many years, but the dielectric properties are still poorly understood. In this study, pure titanium can be thermally oxidized at 800 °C to obtain temperature-stable capacitors, which have high areal capacitance (45.8 nF/cm²), low dielectric loss (<0.02), and a nearly zero temperature coefficient (10 ppm/°C) at 100 kHz. X-ray Diffraction and Energy Dispersive Spectroscopy analysis reveal the coexistence of the rutile phase and oxygen diffusion layers depending on the oxidation temperature. Using complex impedance analysis, equivalent circuit models have been developed. The different Direct current bias and Alternating current voltage tests of the sample show that the capacitance nearly constant up to the breakdown voltage.