Capacitive Silicon Microphone

Altti Torkkeli, Jaakko Saarilahti, Heikki Seppä, Hannu Sipola, Outi Rusanen, Jarmo Hietanen

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

2 Citations (Scopus)

Abstract

A capacitive silicon microphone has been fabricated. The component consists of two freestanding polysilicon membranes, a low-stress bending membrane and a high-stress backplate, which are separated by an air gap. Sound pressure changes the capacitance between the membranes. A back-chamber is arranged by encapsulation and static pressure changes are prevented with small equalisation holes in the bending membrane. The component is fabricated combining bulk and surface micromachining techniques. Silicon substrates are etched in TMAH and sacrificial oxide between the membranes is etched in PSG-etch followed by freeze drying to prevent sticking. The measured acoustic sensitivity of the microphone with 1 × 1 mm2 membrane was 2mV/Pa (1 kHz frequency) and the resolution 35 dB (A-weighted sound level).

Original languageEnglish
Title of host publicationProceedings of the 18th Nordic Semiconductor Meeting
PublisherInstitute of Physics IOP
Pages275-278
Number of pages4
DOIs
Publication statusPublished - 1 Dec 1999
MoE publication typeA4 Article in a conference publication
Event18th Nordic Semiconductor Meeting , 18NSM - Linköping, Sweden
Duration: 8 Jun 199810 Jun 1998

Conference

Conference18th Nordic Semiconductor Meeting , 18NSM
CountrySweden
CityLinköping
Period8/06/9810/06/98

Fingerprint

microphones
Silicon
Membrane
membranes
silicon
freeze drying
Micromachining
acoustics
static pressure
Encapsulation
Equalization
Drying
micromachining
Capacitance
sound pressure
Oxides
Acoustics
chambers
capacitance
Substrate

Cite this

Torkkeli, A., Saarilahti, J., Seppä, H., Sipola, H., Rusanen, O., & Hietanen, J. (1999). Capacitive Silicon Microphone. In Proceedings of the 18th Nordic Semiconductor Meeting (pp. 275-278). Institute of Physics IOP. Physica Scripta: Topical Issues, Vol.. 79 https://doi.org/10.1238/Physica.Topical.079a00275
Torkkeli, Altti ; Saarilahti, Jaakko ; Seppä, Heikki ; Sipola, Hannu ; Rusanen, Outi ; Hietanen, Jarmo. / Capacitive Silicon Microphone. Proceedings of the 18th Nordic Semiconductor Meeting. Institute of Physics IOP, 1999. pp. 275-278 (Physica Scripta: Topical Issues, Vol. 79).
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title = "Capacitive Silicon Microphone",
abstract = "A capacitive silicon microphone has been fabricated. The component consists of two freestanding polysilicon membranes, a low-stress bending membrane and a high-stress backplate, which are separated by an air gap. Sound pressure changes the capacitance between the membranes. A back-chamber is arranged by encapsulation and static pressure changes are prevented with small equalisation holes in the bending membrane. The component is fabricated combining bulk and surface micromachining techniques. Silicon substrates are etched in TMAH and sacrificial oxide between the membranes is etched in PSG-etch followed by freeze drying to prevent sticking. The measured acoustic sensitivity of the microphone with 1 × 1 mm2 membrane was 2mV/Pa (1 kHz frequency) and the resolution 35 dB (A-weighted sound level).",
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Torkkeli, A, Saarilahti, J, Seppä, H, Sipola, H, Rusanen, O & Hietanen, J 1999, Capacitive Silicon Microphone. in Proceedings of the 18th Nordic Semiconductor Meeting. Institute of Physics IOP, Physica Scripta: Topical Issues, vol. 79, pp. 275-278, 18th Nordic Semiconductor Meeting , 18NSM, Linköping, Sweden, 8/06/98. https://doi.org/10.1238/Physica.Topical.079a00275

Capacitive Silicon Microphone. / Torkkeli, Altti; Saarilahti, Jaakko; Seppä, Heikki; Sipola, Hannu; Rusanen, Outi; Hietanen, Jarmo.

Proceedings of the 18th Nordic Semiconductor Meeting. Institute of Physics IOP, 1999. p. 275-278 (Physica Scripta: Topical Issues, Vol. 79).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

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Torkkeli A, Saarilahti J, Seppä H, Sipola H, Rusanen O, Hietanen J. Capacitive Silicon Microphone. In Proceedings of the 18th Nordic Semiconductor Meeting. Institute of Physics IOP. 1999. p. 275-278. (Physica Scripta: Topical Issues, Vol. 79). https://doi.org/10.1238/Physica.Topical.079a00275