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, NSM18 - Linköping, Sweden
    Duration: 8 Jun 199810 Jun 1998

    Publication series

    SeriesPhysica Scripta: Topical Issues
    Volume79
    ISSN0281-1847

    Conference

    Conference18th Nordic Semiconductor Meeting, NSM18
    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).
    @inproceedings{007afc529a2649d2967d19c2be887690,
    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).",
    author = "Altti Torkkeli and Jaakko Saarilahti and Heikki Sepp{\"a} and Hannu Sipola and Outi Rusanen and Jarmo Hietanen",
    year = "1999",
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    doi = "10.1238/Physica.Topical.079a00275",
    language = "English",
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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, NSM18, 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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    AU - Torkkeli, Altti

    AU - Saarilahti, Jaakko

    AU - Seppä, Heikki

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    AU - Rusanen, Outi

    AU - Hietanen, Jarmo

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    AB - 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. 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