Modeling and simulation of sol-gel thin films for monolithic microwave integrated circuit applications

This paper reports on the feasibility study of using sol gel lead zirconate titanate for monolithic microwave integrated circuit (MMIC) thin film capacitors. The films were modeled as thin film microstrip lines (TFMS) and their microwave behaviour was simulated using a commercially available electromagnetic simulator Sonnet. The capacitances were calculated for film thicknesses ranging from 0.1 - 0.3 μm and with dielectric constant from 100 - 1000 over the frequency range of 1 to 100 GHz. In addition, the characteristic impedances of various TFMS lines were also calculated for different line widths. For a 500 dielectric constant/1 μm film thickness structure, the width obtained for a 50 Ω is less than 1 μm. Results of this study show that the proposed sol-gel material can be used for efficient size reduction in MMIC.