Currently, most capacitive micromachined ultrasound transducers, adopting surface sacrificial
technology encounter various problems such as difficult cavity etch, low controllability of membrane thickness
etc., and their operating frequencies are more concentrated in several MHz bandwidths that cannot meet the
requirements of long-distance imaging applications. In order to solve these problems, this paper proposes a new
capacitive ultrasound transducer based on Si-Si bonding technology, which consists of an integration vibration
membrane requiring no extra separate metal film and having high sensitivity, uniform thickness and more
controllable frequencies. This transducer has several great advantages such as: easy processing, simple structure
and process technology, and a high degree of integration. The structure and size of the transducer is determined
by theoretical analysis and finite element analysis software ANSYS, and a process flow is also presented.
Through scanning by SEM and Polytec MSA-400, the processed transducer is tested and analyzed, and the
results are consonant with the simulation, verifying the reliability of the design and fabrication.