As cMUTs (capacitive Micromachined Ultrasonic Transducer) offer numerous advantages
over traditional transducers in terms of efficiency, bandwidth, and cost, they are expected to replace
piezoelectric transducers in many applications. In particular, 2D-array cMUTs have aroused great
interest in the medical engineering society because of their ability to materialize a true volumetric
ultrasonic image. In this study, single element cMUTs with 32 x 32 and 64 x 64 cells were
successfully fabricated. The diameter and thickness of the membrane are 35 and 1000 nm,
respectively, with a sacrificial layer thickness of 600 nm. The electric characteristics of the fabricated
cMUT were measured. Tests on the efficiencies of the cMUT in terms of wave generation and in
terms of detection according to the bias and pulse voltage were performed in an air atmosphere.