Fabrication of silicon condenser microphones using single wafer technology

Author

Scheeper, P.R. ; van der Donk, A.G.H. ; Olthuis, W. ; Bergveld, P.

Author_Institution

Mesa Res. Inst., Twente Univ., Enschede, Netherlands

Volume

1

Issue

3

fYear

1992

fDate

9/1/1992 12:00:00 AM

Firstpage

147

Lastpage

154

Abstract

A condenser microphone design that can be fabricated using the sacrificial layer technique is proposed and tested. The microphone backplate is a 1-μm plasma-enhanced chemical-vapor-deposited (PECVD) silicon nitride film with a high density of acoustic holes (120-525 holes/mm²), covered with a thin Ti/Au electrode. Microphones with a flat frequency response between 100 Hz and 14 kHz and a sensitivity of typically 1-2 mV/Pa have been fabricated in a reproducible way. These sensitivities can be achieved using a relatively low bias voltage of 6-16 V. The measured sensitivities and bandwidths are comparable to those of other silicon microphones with highly perforated backplates. The major advantage of the new microphone design is that it can be fabricated on a single wafer so that no bonding techniques are required

Keywords

elemental semiconductors; gold; micromechanical devices; microphones; silicon; silicon compounds; titanium; 100 Hz to 14 kHz; 6 to 16 V; PECVD; Ti-Au-Si₃N₄-Si; acoustic holes; bias voltage; bonding techniques; condenser microphones; flat frequency response; microphone backplate; microphone design; sacrificial layer technique; single wafer technology; Acoustic testing; Chemicals; Electrodes; Fabrication; Gold; Microphones; Plasma chemistry; Plasma density; Semiconductor films; Silicon;

fLanguage

English

Journal_Title

Microelectromechanical Systems, Journal of

Publisher

ieee

ISSN

1057-7157

Type

jour

DOI

10.1109/84.186394

Filename

186394