Prototyping capacitive-micro-ultrasonic transducers

Capacitive-micro-ultrasonic transducers (CMUT) are considered as prospective probes to replace traditional piezoelectric transducers for high frequency ultrasonic imaging. DC bias voltages are commonly employed to improve their signal/noise ratios and sensitivities. Since expansion limits of CMUT membranes are confined by the bias voltages, bias effects for CMUT devices are investigated and modeled in this research. Also, this research carries out fabrications based upon MEMS processes to prototype the CMUT devices, and describes the manufacturing procedures systematically.