A STUDY OF BARIUM STRONTIUM-TITANATE THIN-FILMS FOR USE IN BYPASS CAPACITORS

Physical and electrical characterization techniques have been applied to the problem of developing a lower temperature process for spin-on B a0.7ST0.3TiO3 thin films and capacitors compatible with on-chip alumin um metallization. The films were prepared by spin-coating from carboxy late precursors and were processed at temperatures between 650 degrees C and 450 degrees C. Capacitors annealed at higher temperatures have a dielectric constant (kappa) of 382, a C/A of 20 fF/mu m(2), and a le akage current density of 2 x 10(-7) A/cm(2) at 3.3 V. Those processed at 450 degrees C show occasionally promising but inconsistent results, correlated using TEM images with locally variable crystallization int o the perovskite phase. The kinetics of the spin-on solution chemical decomposition and crystallization has been investigated through the us e of x-ray diffraction (XRD), thermogravimetric analysis (TGA), and Ra man spectroscopy.