Abstract：Capacitive micromachined ultrasonic transducers (CMUTs) have attracted great attentions in the field of ultrasonic imaging, because the potential of as alternative to piezoelectric ultrasonic sensors. At present, the analysis on CMUTs built by sacrificial layer release technology has less been involved in the analysis of the influence of the processing structures resulted from the releasing process. In this paper, the influence of sacrificial layer release process on CMUTs was analyzed. The finite element analysis software ANSYS was used to analyze the effect of release method on CMUTs’ performance. Moreover, the CMUT with 2.5 MHz was tested using Vibrometer. The results of both simulation and experiment are considerable consistency with an error of 3.9%. It was concluded that the ratio of length and width of membrane on property of CMUT varied much. The resonant frequency of CMUT changed less and the value of percent difference among four modes vary smoothly when the ratio was larger than 4. In addition, the thinner the thickness, the smaller the percentage difference. The effects of supporting walls on vibrating membrane, releasing holes and channels should be considered when building models on CMUT with sacrificial release technique. Finally, the CMUT with 2.5 MHz was tested using a Vibrometer. The results of both simulation and experiment were considerable consistency, which verified the validity of the model presented in this paper.
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