Ultrasonic transducers and methods of manufacturing the same

摘要

A technique for a capacitive micromachined ultrasonic transducer (CMUT) for achieving high transmitted sound pressure and high receiver sensitivity is provided. An opening portion (7a) having a diameter of, for example, about 10 µm is provided at a center portion of a top electrode (7). The opening portion (7a) is provided to include a contact region (14) therewithin where a lower surface of a second insulating film covering a lower surface of the top electrode (7) and an upper surface of a first insulating film covering an upper surface of a bottom electrode (3) are contacted with each other upon driving the ultrasonic transducer when viewed in plan view, so that the ultrasonic transducer has a structure in which the first and second insulating films are not sandwiched by the top electrode (7) and the bottom electrode (3) in the contact region (14).