Lead zirconate titanate thin films on base-metal foils: An approach for embedded high-permittivity passive components

An approach for embedding high-permittivity dielectric thin films into glas s epoxy laminate packages has been developed. Lead lanthanum zirconate tita nate (Pb0.85La0.15-(Zr0.52Ti0.48)(0.96)O-3, PLZT) thin films were prepared using chemical solution deposition on nickel-coated copper foils that were 50 mum thick. Sputter-deposited nickel top electrodes completed the all-bas e-metal capacitor stack. After high-temperature nitrogen-gas crystallizatio n anneals, the PLZT composition showed no signs of reduction, whereas the b ase-metal foils remained flexible. The capacitance density was 300-400 nF/c m(2), and the loss tangent was 0.01-0.02 over a frequency range of 1-1000 k Hz. These properties represent a potential improvement of 2-3 orders of mag nitude over currently available embedded capacitor technologies for polymer ic packages.