MEMS Double Sided Touch Mode Capacitive Pressure Sensor using Silicon Carbide –Aluminium Nitride: Fast analysis

Abstract

Today, pressure sensors occupy the largest market segment in microsystem devices. This is because of their wide range of applications in both commercial and industrial applications. The two major players in MEMS pressure sensors are capacitive and piezoresistive types. Capacitive pressure sensors operating in touch mode have a higher linearity and operating range and are therefore more suitable. Sensor performance can be further enhanced by etching two back to back traditional touch mode capacitive sensors in one substrate. This paper aims to produce a complete mathematical analysis of the double-sided structure of capacitive pressure sensors using Silicon Carbide-Aluminum Nitride as the primary sensing element. The mathematical analysis bypasses the need for using cumbersome simulation software and gives a fast-analytical technique that can be applied to similar simple designs for modelling. The final MATLAB simulations show a significant improvement in both the sensitivity and capacitance generated on using SiC-AlN over Si-SiO2 for the given design.