Diaphragm stress control for sensitivity improvement of piezoelectric ultrasonic microsensors on silicon dioxide diaphragms

Author

Yamashita, K. ; Watanabe, T. ; Yoshizaki, T. ; Noda, M. ; Okuyama, M.

Author_Institution

Kyoto Inst. of Technol., Kyoto, Japan

fYear

2009

fDate

21-25 June 2009

Firstpage

319

Lastpage

322

Abstract

Piezoelectric ultrasonic microsensors have been fabricated using sol-gel derived PZT (Pb(Zr,Ti)O₃) thin films on micromachined silicon dioxide diaphragms made from a normal silicon wafer instead of the conventional SOI (silicon on insulator) wafer process. The layered structure of the PZT capacitor part on the diaphragm has been modified in order to control the total lateral stress in the diaphragm for sensitivity enhancement. The sensors having an island-like structure in the PZT layer have shown over 2 times higher sensitivity than conventional sensors.

Keywords

diaphragms; microsensors; piezoelectric transducers; silicon compounds; stress control; ultrasonic transducers; PZT; PZT capacitor; PZT thin films; diaphragm stress control; piezoelectric ultrasonic microsensors; silicon dioxide diaphragms; Electrodes; Fabrication; Microsensors; Piezoelectric films; Semiconductor thin films; Sensor phenomena and characterization; Silicon compounds; Silicon on insulator technology; Sputtering; Stress control; PZT; Ultrasonic sensor; diaphragm; lateral stress; sensitivity;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensors, Actuators and Microsystems Conference, 2009. TRANSDUCERS 2009. International

Conference_Location

Denver, CO

Print_ISBN

978-1-4244-4190-7

Electronic_ISBN

978-1-4244-4193-8

Type

conf

DOI

10.1109/SENSOR.2009.5285498

Filename

5285498