Silicon microphone based on surface and bulk micromachining

Brauer, Michael; Dehe, A.; Bever, T.; Barzen, S.; Schmitt, Stephan; Füldner, M.; Aigner, Robert

doi:10.1088/0960-1317/11/4/305

Cited by 19 publications

(18 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main advantages of the capacitive silicon sensors are their high sensitivity to pressure and low sensitivity to temperature. Furthermore, the junction field effect transistor with high input impedance must be selected as a detection circuit [2,9]. Figure 2 shows the fabrication process for the air-gap structure MEMS acoustic sensor.…”

Section: The Detection Principlementioning

confidence: 99%

“…The present standard electret condenser microphone (ECM) cannot undergo SMD mounting, because it would be destroyed by the high temperature of the soldering process involved [2]. Researchers now anticipate that the silicon-based condenser MEMS acoustic sensor, which is based on semiconductor technology, will be able to overcome the problem.…”

Section: Introductionmentioning

confidence: 99%

“…The types of MEMS acoustic sensors include piezoresistive [3], condenser [2,4], piezoelectric [1,5] ECM [6]. In this paper, we describe the condenser MEMS acoustic sensor, which is stable against thermal effects, as compared with the other types.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Back-Gated Point Contact

Hashimoto

Miyashita²,

Saku

et al. 2001

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

This paper presents a micromachined air-gap structure microelectromechanical systems (MEMS) acoustic sensor, which is fabricated via assisted high-speed lateral etching and chemical mechanical polishing (CMP). A sandwich structure (LTO/P 2 O 5 /LTO) as a sacrificial layer for the releasing process is proposed to produce an air-gap structure MEMS acoustic sensor. This sandwich structure can be etched selectively in a specific patterned P 2 O 5 layer. In addition, the sandwich structure proved superior to using only low temperature oxide (LTO) layer for the releasing process. We confirmed that the proposed releasing method assisted by lateral etching and CMP is very effective for creating a clean air-gap cavity in MEMS devices. In this work, the air-gap structure MEMS acoustic sensor is based on the capacitance change of a movable thin poly-silicon membrane. A high-gain impedance converter was mounted on a printed circuit board (PCB) with a silicon MEMS acoustic sensor to transform the electrical signal for input acoustic pressure. The membrane size of the MEMS acoustic sensor was 1.5 × 1.5 mm 2 . The sensitivity achieved was about 0.018-5.17 mV Pa −1 . The noise level of the fabricated device was 10 µV Pa −1 .

show abstract

Section: The Detection Principlementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Back-Gated Point Contact

Hashimoto

Miyashita²,

Saku

et al. 2001

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…Research and development of MEMS microphones has been ongoing for some 20 years in order to manufacture a product suitable for customer applications. Requirements such as operation at standard supply voltages [11], support of surface mount packaging [12], use of standard CMOS processes during manufacture [13], and acceptable signal to noise ratio [14] have recently been realised and have led to a breakthrough in MEMS microphone production and usage today. Recent advances in MEMS microphone technology have resulted in the integration of the ADC on the same chip as the microphone and amplifier, producing a digital microphone in which the output of the chip is a Pulse Density Modulated (PDM) version of the incident acoustic signal.…”

Section: Introductionmentioning

confidence: 99%

A digital microphone array for distant speech recognition

Zwyssig

Lincoln

Renals

2010

2010 IEEE International Conference on Acoustics, Speech and Signal Processing

View full text Add to dashboard Cite

In this paper, the design, implementation and testing of a digital microphone array is presented. The array uses digital MEMS microphones which integrate the microphone, amplifier and analogue to digital converter on a single chip in place of the analogue microphones and external audio interfaces currently used. The device has the potential to be smaller, cheaper and more flexible than typical analogue arrays, however the effect on speech recognition performance of using digital microphones is as yet unknown. In order to evaluate the effect, an analogue array and the new digital array are used to simultaneously record test data for a speech recognition experiment. Initial results employing no adaptation show that performance using the digital array is significantly worse (14% absolute WER) than the analogue device. Subsequent experiments using MLLR and CMLLR channel adaptation reduce this gap, and employing MLLR for both channel and speaker adaptation reduces the difference between the arrays to 4.5% absolute WER.

show abstract

“…Various single chip and double chip processes have been reported to enhance microphone frequency response [18][19][20][21][22]. In single chip processes, thick epitaxial growth or siliconon-insulator is required to fabricate rigid backplate, but which increases process complexity.…”

Section: Design Considerationsmentioning

confidence: 99%