Fabrication of Perovskite-Based High-Value Integrated Capacitors by Chemical Solution Deposition

Projected trends for capacitors include increasing capacitance density and decreasing operating voltages, dielectric thickness and process cost. Advances in the fabrication and processing of barium strontium titanate (BST) and lead zirconate titanate (PZT)-based thin films are presented toward attaining these goals in next-generation high-value integrated capacitors. Increasing capacitance density has been demonstrated through the use of large-area electrodes, multilayer structures, and decreased dielectric layer thickness. Capacitance values as high as 10 μF were obtained in a single-layer, 10 cm² film, and layer thicknesses as small as 9 nm have been achieved using chemical solution deposition. Base metal integration results for BST and PZT films are discussed in terms of additional cost and volume reduction; such films have achieved capacitance densities as high as 1.5 μF/cm² and electric fields of 25 V/μm.