FABRICATION OF PMUT USING SILICON ON NOTHING PROCESS FOR FINGERPRINT SENSOR

摘要

Now a day, ultrasonic transducer devices is commonly used in many field. Recently, ultrasonic transducer is fabricated for bio metric applications. The ultrasonic transducer which is fabricated by PZT crystal has some problem. First, devices are became smaller. Fabrication difficulty is dramatically increased. Second devices are places 2D array. Wiring is also very difficult.[1]To solve this problem, many researcher research Micromachined Ultrasonic Transducer.This transducer use electric force(CMUT)[2] or piezoelectric force(PMUT)[3] to vibrate thin membrane. In this research, a PMUT which is fabricated by silicon on nothing process has been demonstrated.