Dielectric and electrical properties of vacuum‐deposited Didymium oxide thin films

Abstract

Abstract Dielectric and electrical properties of sandwich structures of didymium oxide thin films of several thicknesses have been investigated. The variation of capacitance and dielectric dissipation factor (Tan δ) with frequency in these films have been studied. These studies have shown that at room temperature, the capacitance increases with decrease of frequency and the variation is more pronounced at low frequencies. With increase of frequency, the dissipation factor decreases. The increase of capacitance with decrease in frequency has been attributed to the space‐charge polarisation and blocking of charge carriers at the electrodes. The effect of thickness on capacitance and Tan δ in these films have been studied. Current‐Voltage characteristics (I—V) of sandwiched Al‐didymium oxide‐Al structures have been studied at room temperature. These characteristics showed that the breakdown voltage increases and the dielectric strength decreases with increase of oxide film thickness. Conductivity (σ) at room temperature have been calculated to understand the mechanism involved in the conduction process. These results indicated that the conduction in these films is due to Schottky barriers. Breakdown patterns obtained in these structures by the application of de voltage applied across the sandwich structures have been observed with the help of Carl‐Zeiss, Jena, optical microscope. The photomicrographs of these breakdown patterns indicate that the type of breakdown in these structures may be single‐hole breakdown and is proceeded by propagating breakdown.