Investigation and analysis of MEMS based capacitive sensor’s characteristics with the effect of electrode pattern

Precise investigational model of a capacitive micromachined ultrasonic transducer (CMUT) is offered for assessing membrane displacement along with the impact of the top electrode. Silicon nitride (Si₃N₄) selected as membrane material is operated under a DC bias. The top electrode's size and material characteristics are varied in this study to inspect the behavior of the membrane. It appears that when top electrode's thickness increases, displacement reduces because the membrane is subjected to greater loading. This also produces more stress on the membrane resulting in a shift in resonant frequency. Displacement comparison of silicon nitride, silicon carbide and diamond materials has been observed. The detailed analysis of consequence of the top electrode on CMUT performance has also been achieved. Simulations in COMSOL Multiphysics are incorporated in the study to provide strong evidence in favor of the proposed analytical model.