Current-Voltage Characteristics of Electron-Cyclotron-Resonance Sputter-Deposited SrTiO₃ Thin Films

Abstract

Current-voltage characteristics of SrTiO 3 thin films prepared on Pt electrodes by electron-cyclotron-resonance sputtering have been studied. The leakage current characteristics of the films show an ohmiclike conduction for electric field strengths lower than about 1 MV/cm, while the leakage current for higher electric field strengths is limited by Schottky emission. These ohmiclike leakage characteristics in the low-electric-field region show strong dependences on the measurement conditions, namely, the values of voltagestep and measurement delaytime in the conventional stepwise current-voltage ramps. This result is attributed to the absorption current due to the dielectric relaxation phenomena of the SrTiO 3 capacitor. The overall current-voltage characteristics can be explained by Schottky emission from the Pt electrode.