Fabrication of High Tolerance (Ca0.7Sr0.3)(Zr0.8Ti0.2)O-3 Interdigital Capacitors by Aerosol Deposition Based on Optimized Film Thickness and Simulation

Abstract

(Ca0.7Sr0.3)(Zr0.8Ti0.2)O-3 (CSZT) interdigital capacitors (IDCs) were fabricated via the aerosol deposition (AD) for use in embedded capacitor applications with high tolerance and stability. In order to miniaturize the device and to achieve superior electrical properties, the CSZT film thickness was optimized. Furthermore, a simulation was used to design the structure of the IDCs through the Momentum advanced design system (ADS). Consequently, the CSZT films thicker than 1 mu m thick on the Cu substrates were confirmed to have a dense surface morphology, stable dielectric properties with respect to frequency, applied voltage, and temperature, and low leakage currents. A trade-off between the optimum film thickness and the design provided by the simulation resulted in micro-sized CSZT IDCs (90x150 x 2 mu m), and these exhibited a self-resonant frequency of about 9 GHz, capacitance of 1.7 pF up to 8 GHz, and high tolerance for microwave frequencies.