Abstract :
Metallo-organic decomposition derived dielectric thin films of calcium zirconate doped with various concentrations of strontium ((Ca, Sr)ZrO3)
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 CaZrO3 film has amorphous structure with carbonate existing
when annealed at 600 8C, while annealed at 650 8C and above, the carbonate is decomposed and those films crystallize into perovskite phase
without preferred orientation. In addition, the prepared (Ca, Sr)ZrO3 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)ZrO3 films have very low leakage current density and high
breakdown strength; typically, the CaZrO3 film annealed at 650 8C 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
Keywords :
Perovskite-type oxides , Strontium zirconate , Calcium Zirconate , Metallo-organic decomposition , Dielectric thin films