This invention is a novel operation regime for capacitive micromachined ultrasonic transducers (cMUTs). Its method allows the center of the membrane to be in constant contact with the substrate.
Traditionally, cMUTs are operated at a bias voltage lower than the collapse voltage of their membrane. The method of this invention produces a higher electromechanical coupling efficiency than that of a cMUT operating below its collapse voltage and with a larger bandwidth. Furthermore, the process reduces crosstalk between cMUT array elements.
