Study on Predicting the Deformed Membranes based on Silicon Nitride Materials with New Deflection Functions for Calculating the Capacitance of Circular Diaphragm CMUTs

摘要

A new idea is presented which develops a general model predicting the deflection profile of clamped circular diaphragm of Capacitive Micromachined Ultrasonic Transducers (CMUTs) in order to calculate its capacitance. The CMUTs we consider is made of silicon nitride material which is widely used because of its low intrinsic stress. And the general model proposed in this paper is highly accurate in predicting the deformed membranes and exhibits excellent agreement with 3D-FEA results in capacitance deviation less than 1%. These new established deflection functions can be used to implement a much higher accurate design methodology for CMUTs and other MEMS-based capacitive type sensors built with circular diaphragm.