Title :
Pulse-echo ultrasonic fingerprint sensor on a chip
Author :
Tang, H. ; Lu, Y. ; Fung, S. ; Tsai, J.M. ; Daneman, M. ; Horsley, D.A. ; Boser, B.E.
Author_Institution :
Univ. of California, Berkeley, Berkeley, CA, USA
Abstract :
A fully-integrated ultrasonic fingerprint sensor based on pulse-echo imaging is presented. The device consists of a 24×8 Piezoelectric Micromachined Ultrasonic Transducer (PMUT) array bonded at the wafer level to custom readout electronics fabricated in a 180-nm CMOS process. The proposed top-driving bottom-sensing technique minimizes signal attenuation due to the large parasitics associated with high-voltage transistors. With 12V driving signal strength, the sensor takes 24μs to image a 2.3mm by 0.7mm section of a fingerprint.
Keywords :
CMOS image sensors; integrated circuit bonding; micromachining; microsensors; piezoelectric transducers; pulse measurement; readout electronics; sensor arrays; ultrasonic transducer arrays; ultrasonic variables measurement; CMOS process; PMUT array; high-voltage transistor; piezoelectric micromachined ultrasonic transducer array; pulse-echo imaging; pulse-echo ultrasonic fingerprint sensor on a chip; readout electronics; signal attenuation; size 180 mum; time 24 mus; top-driving bottom-sensing technique; voltage 12 V; wafer level bonding; Acoustics; Aluminum nitride; Arrays; Electrodes; Fingerprint recognition; Micromechanical devices; Transducers; Fingerprint sensor; MEMS-CMOS integration; PMUT; Ultrasound transducer;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS), 2015 Transducers - 2015 18th International Conference on
Conference_Location :
Anchorage, AK
DOI :
10.1109/TRANSDUCERS.2015.7181013
