FRACTAL GEOMETRIES IN LATERAL FLUX CAPACITOR DESIGN – EXPERIMENTAL RESULTS

Capacitance density is increased when lateral flux structures are used in CMOS technologies compared to classic parallel-palate capacitors. Lateral-flux capacitors where designed based on three different fractal geometries. Capacitors are designed with and without special MMC metal layer available in some CMOS technologies for capacitor design. For theoretical analysis verification a special ASIC has been designed and fabricated in UMC 0.18um technology. Presented result are obtained by measurement of 5 ICs. Some capacitor structures have much higher capacitance density than classic parallel-plates capacitor without  MMC layer. Few presented structures have higher capacitance density than parallel-plate capacitor made with MMC layer. Capacitors have small process parameters spread.