Mass Detection Using Capacitive Resonant Silicon Sensor

Capacitive resonant mass sensing employing a single-crystalline silicon resonator with a thickness of 250 nm and electrical LC oscillator is presented, and the detectable minimum mass of 1times10^-14 g is obtained in air. It was shown that capacitive detection is less affected to noise than optical detection from the experimental comparison. Using the theoretical model and experimental results, low frequency noise originated in gas adsorption-desorption on sensor surface is evaluated. Finally, mass/stress induced resonance frequency shift due to the adsorption of ethanol and moist vapor is successfully demonstrated.