Structural and electric properties of SrZrO3 thin films on different Pt bottom electrodes

SrZrO3 thin films were deposited on Pt/Ti/SiO2/Si and Pt/TiO2/SiO2/Si substrates by the metal-organic decomposition technology followed by post-annealing at different temperatures ranging from 550 to 800 °C in flowing oxygen atmosphere. The microstructure characteristics of these films were investigated using X-ray diffraction, Fourier transform infrared reflectivity spectroscopy and scanning electron microscopy. Their dielectric and leakage current characteristics were evaluated by a HP-4284A precision LCR meter and a HP-4155B semiconductor parameter analyzer, respectively. The phase transformation and crystallinity results indicate that the film has amorphous structure with carbonate existing when annealed at 550 °C; however when annealed at 600 °C and above, the carbonate is decomposed and those films crystallize into the Perovskite phase. The dielectric constant of SrZrO3 is above 22 with little dispersion in a frequency range from 100 Hz to 1 MHz. The results also indicate that when annealed above 650 °C, the films using Pt/TiO2/SiO2/Si show much better leakage properties compared with those using Pt/Ti/SiO2/Si. And even annealed at 800 °C, the films deposited on Pt/TiO2/SiO2/Si substrate still have good leakage properties.