Olcum, SelimOǧuz, KaanŞenlik, Muhammed N.Yamaner F. Y.Bozkurt, A.Atalar, AbdullahKöymen, Hayrettin2016-02-082016-02-082009-09http://hdl.handle.net/11693/28638Date of Conference: 20-23 Sept. 2009Conference name: 2009 IEEE International Ultrasonics SymposiumIn this work we have designed, fabricated and tested CMUTs as underwater transducers. Single CMUT membranes with three different radii and 380 microns of thickness are fabricated for the demonstration of an underwater CMUT element. The active area of the transducer is fabricated on top of a 3″ silicon wafer. The silicon wafer is bonded to a gold electrode coated glass substrate wafer 10 cm in diameter. Thermally grown silicon oxide layer is used as the insulation layer between membrane and substrate electrodes. Electrical contacts and insulation are made by epoxy layers. Single CMUT elements are tested in air and in water. Approximately 40% bandwidth is achieved around 25 KHz with a single underwater CMUT cell. Radiated pressure field due to second harmonic generation when the CMUTs are driven with high sinusoidal voltages is measured. ©2009 IEEE.EnglishAnodic bondingCapacitive micromachined ultrasonic transducersComponentSecond harmonic generationUnderwater transducersActive areaAnodic bondingCapacitive micromachined ultrasonic transducerCoated glass substratesElectrical contactsEpoxy layersGold electrodesInsulation layersMicromachinedPressure fieldSilicon oxide layersSinusoidal voltageSubstrate electrodesUnderwater transducersFabricationGold coatingsHarmonic analysisHarmonic generationNonlinear opticsSemiconducting silicon compoundsSilicon oxidesSilicon wafersSubstratesTransducersUltrasonic equipmentUltrasonic measurementUltrasonic wavesUltrasonicsWafer bondingUltrasonic transducersConference Paper10.1109/ULTSYM.2009.5441699