Free Standing Stress Amplification Structure for Ultrasensitive 3C-SiC/Si Pressure Sensor

Abstract

This paper presents an innovative stress amplification approach for enhancing the sensitivity of piezoresistive pressure sensors. The structure consists of two pillars raised from the membrane supporting a released 3C-SiC micro-beam which acts as the sensing element. The proposed design was demonstrated using a 3C-SiC/Si heterostructure. Experimental results found our device highly sensitive, with a high sensitivity of 0.1328 kPa−1. The sensitivity improvement was attributed to the stress-amplification phenomenon observed in our free-standing structure. Analytical and numerical methods confirmed that our device increases the stress/sensitivity by 750% over a traditional membrane structure.