Effect of the Surface Roughness on the Detecting Capacitance

With the MEMS technology advancement, electronic devices are miniaturized at every development node. The surface roughness is affecting the detecting capacitance of MEMS device because surface to volume ratio is increasing rapidly. A novel model with one rough electrode is investigated in this paper. The impacts of surface roughness on detecting capacitance are analyzed. The image of height percentage is used to describe the surface roughness of electrode sample. The function of the surface roughness is obtained according the method of curve fitting. The effect of surface roughness on the capacitance is calculated. The results demonstrate the capacitance increases with the surface roughness.