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 language | English |
|---|---|
| Title of host publication | Proceedings of the 18th Nordic Semiconductor Meeting |
| Publisher | Institute of Physics IOP |
| Pages | 275-278 |
| Number of pages | 4 |
| DOIs | |
| Publication status | Published - 1 Dec 1999 |
| MoE publication type | A4 Article in a conference publication |
| Event | 18th Nordic Semiconductor Meeting, NSM18 - Linköping, Sweden Duration: 8 Jun 1998 → 10 Jun 1998 |
Publication series
| Series | Physica Scripta: Topical Issues |
|---|---|
| Volume | 79 |
| ISSN | 0281-1847 |
Conference
| Conference | 18th Nordic Semiconductor Meeting, NSM18 |
|---|---|
| Country | Sweden |
| City | Linköping |
| Period | 8/06/98 → 10/06/98 |
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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 proceeding › Conference article in proceedings › Scientific › peer-review
TY - GEN
T1 - Capacitive Silicon Microphone
AU - Torkkeli, Altti
AU - Saarilahti, Jaakko
AU - Seppä, Heikki
AU - Sipola, Hannu
AU - Rusanen, Outi
AU - Hietanen, Jarmo
PY - 1999/12/1
Y1 - 1999/12/1
N2 - 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).
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).
UR - http://www.scopus.com/inward/record.url?scp=0011027913&partnerID=8YFLogxK
U2 - 10.1238/Physica.Topical.079a00275
DO - 10.1238/Physica.Topical.079a00275
M3 - Conference article in proceedings
AN - SCOPUS:0011027913
T3 - Physica Scripta: Topical Issues
SP - 275
EP - 278
BT - Proceedings of the 18th Nordic Semiconductor Meeting
PB - Institute of Physics IOP
ER -