ZERO-BIAS CAPACITIVE MICROMACHINED ULTRASONIC TRANSDUCERS AND FABRICATION METHOD THEREOF

摘要

The present invention provides a zero-bias capacitive micromachined ultrasonic transducer element, comprising: a substrate having a lower electrode formed therein; a membrane structure that structurally supports an upper electrode over the lower electrode, wherein the upper electrode has at least one protruding part thereunder; a cavity between the substrate and the membrane structure; and a polymeric material coated on an inner surface of the cavity. The fabrication method of the zero-bias capacitive micromachined ultrasonic transducer element is also provided.