ELASTIC WAVE TRANSDUCER, ELASTIC WAVE TRANSDUCER ARRAY, ULTRASONIC PROBE, AND ULTRASONIC IMAGING APPARATUS

摘要

An elastic wave transducer includes a substrate (101) having a lower electrode, a support member (102) formed on the substrate, and a membrane (103) that is held by the support member and has an upper electrode. The membrane has a first region (105) that is in contact with the support member, and a second region (106) that is out of contact with said support member and is deformed by receiving an elastic wave. The second region of the membrane has a region in which the bulk density of the second region becomes smaller in accordance with an increasing distance thereof from the first region of the membrane. In addition, the second region has a bulk density ratio that is larger than or equal to 0.1 and is less than or equal to 0.5.