Metallo-organic decomposition derived (Ca, Sr)ZrO 3 dielectric thin films on Pt coated Si substrate

Abstract

Metallo-organic decomposition derived dielectric thin films of calcium zirconate doped with various concentrations of strontium ((Ca, Sr)ZrO 3) were prepared on Pt coated silicon substrate. Mainly in this paper, we present the investigations of their structural developments and present their electric and dielectric properties as well. The structural developments show that the CaZrO 3 film has amorphous structure with carbonate existing when annealed at 600 °C, while annealed at 650 °C and above, the carbonate is decomposed and those films crystallize into perovskite phase without preferred orientation. In addition, the prepared (Ca, Sr)ZrO 3 films with their Zr–O bonds affected by strontium doping are homogenous and stable as solid solutions in any concentration of strontium and all Bragg diffraction characteristics for the films shift downward with the increase in the concentration of strontium. Moreover, the electric properties show that the (Ca, Sr)ZrO 3 films have very low leakage current density and high breakdown strength; typically, the CaZrO 3 film annealed at 650 °C has the leakage current density approximately 9.5 × 10 −8 A cm −2 in the field strength of 2.6 MV cm −1. Furthermore, the dielectric properties show that their dielectric constants are higher than 12.8 with very little dispersion in the frequency range from 100 Hz to 1 MHz and are independent of applied dc bias as well. The dielectric properties, in combination with the electric properties, make the materials promising candidates for high-voltage and high-reliability capacitor applications.