High Temperature Phase Transitions Observed in Oxygen Deficient TiO2-x Thin Films

Abstract

The results of the study on dielectric properties of TiO2 thin films at high temperature T up to 900ºC are reported. High-temperature (Tc ~ 700ºC) anomalous behavior of dielectric constant was observed in both anatase and rutile TiO2 thin films. Dielectric properties of TiO2 thin films were studied in air, in controlled Ar/O2 atmospheres, and in vacuum using silicon-based Metal-Insulator-Semiconductor (MIS) Au/TiO2/Si capacitors. Anatase and rutile TiO2 thin films were prepared by CVD method using Ti(OPri)4 and Ti(dpm)2(OPri)2 as precursors (dpm = 2,2,6,6-tetramethylheptane-3,5-dione and Pri = isopropyl).