Title :
In-plane polarization for high sensitivity ferroelectric MEMS ultrasound transducers
Author :
Bernstein, J.J. ; Bottari, J. ; Houston, K. ; Kirkos, G. ; Miller, R. ; Xu, B. ; Ye, Y. ; Cross, L.E.
Author_Institution :
Charles Stark Draper Lab. Inc., Cambridge, MA, USA
Abstract :
This paper discusses the design of advanced micromachined ferroelectric ultrasound transducers for use at 3 MHz. 16×16 arrays of resonant monomorph sensors have been constructed, with sol-gel PZT as the active ferroelectric layer deposited on insulating layers of ZrO2 and SiO2. A novel in-plane polarization of the PZT is used to maximize sensitivity, while trading off reduced output capacitance to match the CMOS buffer electronics. This results in about 30 dB improved sensitivity compared to conventional polarizing across the thickness of the PZT layer. An equivalent circuit model as well as Finite Element results are presented. Test results are reported including transmit response, receive sensitivity
Keywords :
dielectric polarisation; equivalent circuits; ferroelectric devices; finite element analysis; lead compounds; microsensors; ultrasonic transducer arrays; 3 MHz; CMOS buffer electronics; PZT; PZT sol-gel layer; PbZrO3TiO3; SiO2; ZrO2; equivalent circuit; ferroelectric MEMS ultrasound transducer; finite element model; in-plane polarization; insulating layer; micromachining; output capacitance; receive sensitivity; resonant monomorph sensor array; transmit response; Capacitance; Ferroelectric materials; Insulation; Micromechanical devices; Polarization; Resonance; Sensor arrays; Ultrasonic imaging; Ultrasonic transducer arrays; Ultrasonic transducers;
Conference_Titel :
Applications of Ferroelectrics, 2000. ISAF 2000. Proceedings of the 2000 12th IEEE International Symposium on
Conference_Location :
Honolulu, HI
Print_ISBN :
0-7803-5940-2
DOI :
10.1109/ISAF.2000.941508
