Properties of barium titanate (BaTiO3) thin films grown on silicon by rf magnetron sputtering

Thin films of BaTiO3 were deposited on p-Si substrates by rf magnetron sputtering in order to investigate their suitability for use in ac thin film electroluminescent (ACTFEL) devices and dynamic RAM (DRAM) applications. Post-growth annealing at 700 degrees C and the subsequent deposition of Al contacts resulted in the creation of Al/BaTiO3/p-Si metal-insulator-semiconductor devices. The electronic and structural properties of the films were examined by admittance spectroscopy, current-voltage and transient current measurements, and X-ray diffraction (XRD) characterization. Analysis of the XRD spectra showed the polycrystalline nature of the films but also the presence of an amorphous phase. The electrical measurements revealed a high dielectric constant, around 60, a charge storage capacity exceeding 3 mu C cm(-2) and a total charge trapped inside the oxide of around 50 nC cm(-2) while the density of traps at the BaTiO3/p-Si interface was found to be as high as 1 x 10(12) cm(-2) eV(-1) These results indicate that the films are suitable for both DRAM and ACTFEL applications.