High- $k$ Thin-Film Capacitors With Conducting Oxide Electrodes on Glass Substrates for Power-Supply Applications

High-k barium strontium titanate (BST) thin films were deposited onto glass substrates to demonstrate integrated capacitors for power supply in high-speed digital packages. Ferroelectric BST films were sputter deposited onto solution-derived lanthanum nickel oxide (LNO) electrodes. Zirconium oxide was studied for the first time as a barrier between glass and LNO electrodes to prevent electrode (LNO) interdiffusion into the glass substrate. The LNO and BST films were annealed in an oxygen-rich atmosphere at 650°C. A capacitance density of 20-30 nF/mm
²
was obtained at an operating voltage of 3 V. Leakage currents of 1-10 nA/nF were measured up to 3 V. These properties demonstrate the potential for low-cost high-k thin-film decoupling capacitors in 2-D, 2.5-D, and 3-D glass interposers. A process to integrate and test such capacitors on glass substrates using sequential dielectric and electrode patterning is also demonstrated.