Surface and bulk micromachined dual back-plate condenser microphone

Author

Martin, T. ; Kadirvel, Karthik ; Fox, R.M. ; Nishider, T. ; Liu, J. ; Sheplak, M.

Author_Institution

Dept. of Electr. & Comput. Eng., Florida Univ., Gainesville, FL, USA

fYear

2005

fDate

30 Jan.-3 Feb. 2005

Firstpage

319

Lastpage

322

Abstract

This paper presents the design, fabrication, and characterization of a dual back-plate condenser microphone. The microphone was designed for aeroacoustic applications where a high dynamic range and high bandwidth are key requirements. It was fabricated using the SUMMiT V process at Sandia National Laboratories. The microphone has a 2.25 μm thick circular diaphragm with a 230 μm radius and 2 μm gap between each back-plate. The device has demonstrated a sensitivity of 282 μV/Pa, a linear response up to 160 dB, a noise floor of 42 dB/√Hz at 1 kHz in a 1 Hz bin, and a flat frequency response up to 20 kHz; the theoretical bandwidth exceeds 100 kHz.

Keywords

diaphragms; micromachining; microphones; 2 micron; 2.25 micron; 230 micron; SUMMiT V process; Sandia National Laboratories; aeroacoustic applications; bulk micromachining; dual back-plate condenser microphone; surface micromachining; Acoustic noise; Bandwidth; Capacitors; Fabrication; Laboratories; Micromechanical devices; Microphones; Optical sensors; Piezoresistance; Temperature sensors;

fLanguage

English

Publisher

ieee

Conference_Titel

Micro Electro Mechanical Systems, 2005. MEMS 2005. 18th IEEE International Conference on

ISSN

1084-6999

Print_ISBN

0-7803-8732-5

Type

conf

DOI

10.1109/MEMSYS.2005.1453931

Filename

1453931