Preparation of barium strontium titanate thin film capacitors on silicon by metallorganic decomposition

Abstract

Barium strontium titanate films were deposited on 100-mm-diam silicon wafers by metallorganic decomposition. Highly uniform films ranging up to 250 nm in thickness were obtained. Scanning electron beam micrographs revealed dense, crack-free, low porosity films having grain sizes in the submicron range. Dissipations (tan δ) of less than 0.01 and capacitance densities up to 204 nF/cm2 were measured for 190-nm-thick films. These films had dc leakage currents of 0.2 μA/cm2 or less for bias voltages up to 10 V. They also exhibited relatively small temperature coefficients of capacitance. A patterning process was developed that permitted feature resolution down to 5 μm.