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 sput tering in order to investigate their suitability for use in ac thin film el ectroluminescent (ACTFEL) devices and dynamic RAM (DRAM) applications. Post -growth annealing at 700 degrees C and the subsequent deposition of Al cont acts resulted in the creation of Al/BaTiO3/p-Si metal-insulator-semiconduct or devices. The electronic and structural properties of the films were exam ined by admittance spectroscopy, current-voltage and transient current meas urements, and X-ray diffraction (XRD) characterization. Analysis of the XRD spectra showed the polycrystalline nature of the films but also the presen ce of an amorphous phase. The electrical measurements revealed a high diele ctric 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 a s 1 x 10(12) cm(-2) eV(-1) These results indicate that the films are suitab le for both DRAM and ACTFEL applications.