Deposition and etching of diaphragm and sacrificial layer in novel MEMS capacitive microphone structure

Bahram Azizollah Ganji, Burhanuddin Yeop Majlis

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

This paper will describe how a novel single-chip capacitive microphone was successfully fabricated on silicon wafer using MEMS process. The capacitive microphones generally consist of a diaphragm, back plate and air gap. The novelties of the method relies on the moveable aluminum (Al) diaphragm positioned over the backplate electrode, where the diaphragm includes a plurality of holes to allow the air in the gap between the electrode and the diaphragm to escape and thus reducing acoustical damping in the microphone. Spin-on-glass (SOG) was used as a sacrificial and isolating layer. Back plate is mono crystalline silicon wafer, that it is more stiff. Compared with the previously works, this microphone has several advantages: By making acoustic holes in diaphragm, no KOH etching is needed to make back chamber, thus the chip size of microphone is reduced. The fabrication process use minimal number of layers and masks to reduce the fabrication cost. SOG sacrificial layer is easy to deposition by spin coater and also easy to release by PAD etch solution. The temperature used for fabrication is less than 200 °C, thus reducing temperature induced damages. The diaphragm size is 0.5 × 0.5 mm 2 which is smaller than conventional MEMS capacitive microphone. Since Al diaphragm is electrically conductive, thus no extra electrode is needed.

Original languageEnglish
Title of host publicationIEEE International Conference on Semiconductor Electronics, Proceedings, ICSE
Pages232-238
Number of pages7
DOIs
Publication statusPublished - 2008
Event2008 IEEE International Conference on Semiconductor Electronics, ICSE 2008 - Johor Bahru, Johor
Duration: 25 Nov 200827 Nov 2008

Other

Other2008 IEEE International Conference on Semiconductor Electronics, ICSE 2008
CityJohor Bahru, Johor
Period25/11/0827/11/08

Fingerprint

Microphones
Diaphragms
MEMS
Etching
Aluminum
Silicon wafers
Fabrication
Electrodes
Glass
Air
Masks
Damping
Acoustics
Crystalline materials
Temperature
Costs

Keywords

  • Deposition
  • Diaphragm
  • Etching
  • MEMS microphone
  • Sacrificial layer

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

Cite this

Ganji, B. A., & Yeop Majlis, B. (2008). Deposition and etching of diaphragm and sacrificial layer in novel MEMS capacitive microphone structure. In IEEE International Conference on Semiconductor Electronics, Proceedings, ICSE (pp. 232-238). [4770314] https://doi.org/10.1109/SMELEC.2008.4770314

Deposition and etching of diaphragm and sacrificial layer in novel MEMS capacitive microphone structure. / Ganji, Bahram Azizollah; Yeop Majlis, Burhanuddin.

IEEE International Conference on Semiconductor Electronics, Proceedings, ICSE. 2008. p. 232-238 4770314.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Ganji, BA & Yeop Majlis, B 2008, Deposition and etching of diaphragm and sacrificial layer in novel MEMS capacitive microphone structure. in IEEE International Conference on Semiconductor Electronics, Proceedings, ICSE., 4770314, pp. 232-238, 2008 IEEE International Conference on Semiconductor Electronics, ICSE 2008, Johor Bahru, Johor, 25/11/08. https://doi.org/10.1109/SMELEC.2008.4770314
Ganji BA, Yeop Majlis B. Deposition and etching of diaphragm and sacrificial layer in novel MEMS capacitive microphone structure. In IEEE International Conference on Semiconductor Electronics, Proceedings, ICSE. 2008. p. 232-238. 4770314 https://doi.org/10.1109/SMELEC.2008.4770314
Ganji, Bahram Azizollah ; Yeop Majlis, Burhanuddin. / Deposition and etching of diaphragm and sacrificial layer in novel MEMS capacitive microphone structure. IEEE International Conference on Semiconductor Electronics, Proceedings, ICSE. 2008. pp. 232-238
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