Two clover-shaped piezoresistive silicon microphones for photo acoustic gas sensors

Low cost CO2 gas sensors for demand-controlled ventilation can lower the energy consumption and increase comfort and hence productivity in office buildings and schools. The photo aoustic principle offers very high sensitivity and selectivity when used for gas trace analysis. Current systems are too expensive and large for in-duct mounting. Here, the design, modeling, fabrication and characterization of two micromachined silicon microphones with piezoresistive readout designed for low cost photo acoustic gas sensors are presented. The microphones have been fabricated using a foundry MPW service. One of the microphones has been fabricated using an additional etching step that allows etching through membranes with large variations in thickness. To increase sensitivity and resolution, a design based on a released membrane suspended by four beams was chosen. The microphones have been characterized for frequencies up to 1 kHz and 100 Hz, respectively. Averaged sensitivities are measured to be 30 µV/(V × Pa) and 400 µV/(V × Pa). The presented microphones offer increased sensitivities compared to similar sensors.

[1]  Michael J. Toohey,et al.  Electrodes for nanodot-based gas sensors , 2005 .

[2]  Giuseppe Barillaro,et al.  Analysis, simulation and relative performances of two kinds of serpentine springs , 2005 .

[3]  Wouter Olthuis,et al.  High-performance condenser microphone with fully integrated CMOS amplifier and DC-DC voltage converter , 1998 .

[4]  Peter Werle,et al.  A review of recent advances in semiconductor laser based gas monitors , 1998 .

[5]  Elmer V Carlson,et al.  Noise in miniature microphones. , 2002, The Journal of the Acoustical Society of America.

[6]  Ingemar Lundström,et al.  Twenty-five years of field effect gas sensor research in Linköping , 2007 .

[7]  A. Miklós,et al.  Application of acoustic resonators in photoacoustic trace gas analysis and metrology , 2001 .

[8]  Jun Ma,et al.  On the single-chip condenser miniature microphone using DRIE and backside etching techniques , 2003 .

[9]  J. Wortman,et al.  Young's Modulus, Shear Modulus, and Poisson's Ratio in Silicon and Germanium , 1965 .

[10]  Sang Choon Ko,et al.  Micromachined piezoelectric membrane acoustic device , 2003 .

[11]  S. D. Collins,et al.  Study of electrochemical etch-stop for high-precision thickness control of silicon membranes , 1989 .

[12]  R N Miles,et al.  A low-noise differential microphone inspired by the ears of the parasitoid fly Ormia ochracea. , 2009, The Journal of the Acoustical Society of America.

[13]  Jianmin Miao,et al.  Sensitivity-improved silicon condenser microphone with a novel single deeply corrugated diaphragm , 2001 .

[14]  Jonathan Swingler,et al.  The effect of relative humidity, temperature and electrical field on leakage currents in piezo-ceramic actuators under dc bias , 2009 .

[15]  Burhanuddin Yeop Majlis,et al.  Design and fabrication of a new MEMS capacitive microphone using a perforated aluminum diaphragm , 2009 .

[16]  N. Bârsan,et al.  Micromachined metal oxide gas sensors: opportunities to improve sensor performance , 2001 .

[17]  Samara L. Firebaugh,et al.  Miniaturization and integration of photoacoustic detection , 2002 .

[18]  Zhijian Li,et al.  Design and fabrication of silicon condenser microphone using corrugated diaphragm technique , 1996 .

[19]  S. Shtrikman,et al.  Resonant optoacoustic cells for trace gas analysis , 1978 .

[20]  Jerry Workman.  A Review of Process near Infrared Spectroscopy: 1980–1994 , 1993 .

[21]  Suan Hee Seah,et al.  Design considerations in micromachined silicon microphones , 2002 .

[22]  Seung S. Lee,et al.  Piezoelectric microphone built on circular diaphragm , 2008 .

[23]  Hyu-Sang Kwon,et al.  Double-chip condenser microphone for rigid backplate using DRIE and wafer bonding technology , 2007 .

[24]  Bernhard Müller,et al.  Single-chip condenser microphone using porous silicon as sacrificial layer for the air gap , 2001 .

[25]  M. Fuldner,et al.  Analytical analysis and finite element simulation of advanced membranes for silicon microphones , 2005, IEEE Sensors Journal.

[26]  Gisela Hess,et al.  A subminiature condenser microphone with silicon nitride membrane and silicon back plate , 1989 .

[27]  R. Schellin,et al.  A silicon subminiature microphone based on piezoresistive polysilicon strain gauges , 1992 .

[28]  Marc P.Y. Desmulliez,et al.  Fabrication of a MEMS accelerometer to detect heart bypass surgery complications , 2009 .

[29]  D. Pribat,et al.  Carbon nanotubes based transistors as gas sensors: State of the art and critical review , 2009 .

[30]  A. Ando,et al.  High-Performance Condenser Microphone With Single-Crystalline Silicon Diaphragm and Backplate , 2007, IEEE Sensors Journal.

[31]  Heng-Chuan Kan,et al.  Modeling of corrugated diaphragms for condenser microphones , 2007, 2007 International Microsystems, Packaging, Assembly and Circuits Technology.

[32]  Gisela Hess,et al.  Silicon condenser microphones with corrugated silicon oxide/nitride electret membranes , 2002 .

[33]  Peter Enoksson,et al.  A free-hanging strain-gauge for ultraminiaturized pressure sensors , 2002 .

[34]  Sébastien Candel,et al.  Combustion control and sensors: a review , 2002 .

[35]  K. Schjolberg-Henriksen,et al.  Sensitive and Selective Photo Acoustic Gas Sensor Suitable for High Volume Manufacturing , 2006, 2006 5th IEEE Conference on Sensors.

[36]  Marcelo J. Dapino,et al.  Microphone based on Polyvinylidene Fluoride (PVDF) micro-pillars and patterned electrodes , 2009 .

[37]  Per Ohlckers,et al.  Advantages and Limitations of Diamond-Like Carbon as a MEMS Thin Film Material , 2008 .

[38]  Ilkka Tittonen,et al.  Fabrication and characterization of an ultrasensitive acousto-optical cantilever , 2007 .

[39]  Andreas Vogl,et al.  High-resolution pressure sensor for photo acoustic gas detection , 2006 .

[40]  A. Tam.  Applications of photoacoustic sensing techniques , 1986 .

[41]  Pirmin Hermann Otto Rombach,et al.  Silicon microphones - a Danish perspective , 1998 .

[42]  Alfons Dehe,et al.  Silicon microphone development and application , 2007 .

[43]  P. Ohlckers,et al.  A clover shaped silicon piezoresistive microphone for miniaturiz Photoacoustic Gas sensors , 2009, 2009 Symposium on Design, Test, Integration & Packaging of MEMS/MOEMS.

[44]  B. Reedy,et al.  Temperature modulation in semiconductor gas sensing , 1999 .

[45]  G. Su,et al.  Serpentine Spring Corner Designs for Micro-Electro-Mechanical Systems Optical Switches with Large Mirror Mass , 2005 .

[46]  J. Bergqvist,et al.  Capacitive microphone with a surface micromachined backplate using electroplating technology , 1994 .

[47]  Ib-Rune Johansen,et al.  Optical MEMS for infrared gas sensors , 2000, 2000 IEEE/LEOS International Conference on Optical MEMS (Cat. No.00EX399).

[48]  D. A. van den Ende,et al.  Lifetime of piezoceramic multilayer actuators: Interplay of material properties and actuator design , 2009 .

[49]  Stefano Brugioni,et al.  Liquid crystal twisted nematic light modulator for the infrared region , 2004 .