Electrostatically Driven Touch-Mode Poly-SiC Microspeaker

Author

Roberts, Robert C. ; Du, Jiangang ; Ong, Andojo Ongkodjojo ; Li, Dachao ; Zorman, Christian A. ; Tien, Norman C.

Author_Institution

Case Western Reserve Univ., Cleveland

fYear

2007

fDate

28-31 Oct. 2007

Firstpage

284

Lastpage

287

Abstract

This paper presents an electrostatically driven microspeaker utilizing a SiC membrane operating in the touch-mode configuration. The device is formed using conventional wafer bonding to hermetically seal a low-stress, heavily-doped polycrystalline 3C-SiC (poly-SiC) membrane to a bulk micromachined silicon back-plate containing a thin oxide insulating layer. The bonding process is done in high vacuum, causing the poly-SiC membrane to flex down into contact with the back-plate when exposed to atmospheric pressure. Sound Pressure Level (SPL) measurements were recorded for a device with a poly-SiC membrane thickness of 1 mum, a diameter of 800 mum, and a diaphragm/back-plate spacing of 8 mum. At a distance of 10 mm, a maximum SPL of 73 dB was found at a frequency of 16.59 kHz.

Keywords

acoustoelectric transducers; electrostatic devices; micromechanical devices; silicon compounds; wafer bonding; wide band gap semiconductors; SiC; bulk micromachined silicon back-plate; electrostatically driven touch-mode microspeaker; polycrystalline membrane; sound pressure level measurements; wafer bonding; Atmospheric measurements; Biomembranes; Bonding processes; Frequency; Hermetic seals; Insulation; Pressure measurement; Silicon carbide; Thickness measurement; Wafer bonding;

fLanguage

English

Publisher

ieee

Conference_Titel

Sensors, 2007 IEEE

Conference_Location

Atlanta, GA

ISSN

1930-0395

Print_ISBN

978-1-4244-1261-7

Electronic_ISBN

1930-0395

Type

conf

DOI

10.1109/ICSENS.2007.4388392

Filename

4388392