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Quanbo Zou - One of the best experts on this subject based on the ideXlab platform.

  • Modeling and characterization of a silicon Condenser Microphone
    Journal of Micromechanics and Microengineering, 2003
    Co-Authors: William Wang, Rongming Lin, Quanbo Zou
    Abstract:

    A single-chip silicon Condenser Microphone with a single deeply corrugated diaphragm (SDCD) has been developed. The fundamental characteristics, including mechanical sensitivity, resonance frequency, zero-pressure offset and temperature dependence of the diaphragm, are simulated using a finite element model (FEM). An analytical model is presented to validate that the higher mechanical sensitivity of the SDCD compared with the flat diaphragm with clamped edges is achieved by both releasing the residual stress and reducing the effective mechanical constant of the diaphragm structure. The electrostatic–structural coupling FEM analysis is used in combination with equivalent circuits to evaluate and understand the mechanical, electrostatic and acoustic performances of the Microphone. The measurements show reasonable agreements with the theoretical predictions.

  • sensitivity improved silicon Condenser Microphone with a novel single deeply corrugated diaphragm
    Sensors and Actuators A-physical, 2001
    Co-Authors: R M Lin, Jianmin Miao, Huatsoon Kek, Quanbo Zou
    Abstract:

    Abstract A micro-machined Condenser Microphone, with a novel single deeply corrugated diaphragm (SDCD) for sound sensing, has been developed to improve mechanical-sensitivity by both releasing the initial stress and decreasing the mechanical stiffness of the diaphragm. Both theoretical analysis and finite-element-model (FEM) simulation results show the obvious improvement in mechanical-sensitivity of the SDCD Microphone, compared with the Microphones of conventional structures. The proposed Microphone has been designed with a single-wafer construction and fabricated using silicon micro-machining technologies. The wafer level measurements show that the sensitivity is as high as about 10 mV/Pa under 5 V dc bias. About −3 dB bandwidth of nearly 20 kHz has been obtained by proper design of perforated holes.

  • theoretical and experimental studies of single chip processed miniature silicon Condenser Microphone with corrugated diaphragm
    Sensors and Actuators A-physical, 1997
    Co-Authors: Quanbo Zou, Litian Liu
    Abstract:

    Abstract A miniature single-chip-processed silicon Condenser Microphone with a corrugated diaphragm has been developed. The Microphone with a highly sensitive diaphragm 1 mm2 in area and a highly rigid backplate is fabricated in a single-chip process. The finite-element method (FEM) and equivalent-circuit method have been used to evaluate the mechanical and acoustic performance. Diaphragms with different corrugation configurations are simulated and tested, and an optimized structure of high mechanical sensitivity has been achieved. Microphone sensitivities in the range 9.6–14.2 mV Pa−1 have been recorded under bias voltages of 10–20 V, with good reproducibility. The frequency bandwidth of the devices is between 9 and 16 kHz. The simulated results are in good agreement with the experiments.

  • Design and Fabrication of Silicon Condenser Microphone Using Corrugated
    1996
    Co-Authors: Quanbo Zou
    Abstract:

    A novel silicon Condenser Microphone with a cor- rugated diaphragm has been proposed, designed, fabricated and tested. The Microphone is fabricated on a single wafer by use of silicon anisotropic etching and sacrificial layer etching techniques, so that no bonding techniques are required. The introduction of well-performing corrugations has greatly increased the me- chanical sensitivities of the Microphone diaphragms due to the reduction of the initial stress in the thin fdms. For the purpose of further decreasing the thin film stress, composite diaphragms consisting of multilayer (polySi/Siz N,/polySi) materials have been fabricated, reducing the initial stress to a much lower level of about 70 MPa in tension. Three types of corrugation placements and several corrugation depths in a diaphragm area of 1 mm2 have been designed and fabricated. Microphones with flat frequency response between 100 Hz and 8-16 kHz and open- circuit sensitivities as high as 8.1-14.2 mV/Pa under the bias voltages of 10-25 V have been fabricated in a reproducible way. The experimental results proved that the corrugation technique is promising for silicon Condenser Microphone. (185)

A Stoffel - One of the best experts on this subject based on the ideXlab platform.

  • single chip Condenser Microphone using porous silicon as sacrificial layer for the air gap
    Sensors and Actuators A-physical, 2001
    Co-Authors: W Kronast, B Muller, W Siedel, A Stoffel
    Abstract:

    Abstract A single-chip IC-compatible silicon Condenser Microphone with a highly sensitive silicon nitride diaphragm and a rigid monocrystalline silicon counterelectrode with acoustic holes was designed and built. Porous silicon with its high dissolution rate in 1% KOH was used as an auxiliary sacrificial layer in combination with sputtered SiO 2 to define the air gap. This results in low parasitic capacitances and a Microphone structure where the diaphragm is coplanar with its suspensions. The rigid backelectrode is undistorted, the diaphragm under low tensile stress, a prerequisite for high sensitivity. Microphones of different dimensions of round and square electrodes with single diaphragms and diaphragm arrays were built and packaged in round chip carriers. The open loop sensitivity is in the mV/Pa range depending on the type of Microphone. The frequency response goes beyond 25 kHz for an air gap of 1.3 μm.

  • single chip Condenser Microphone using porous silicon as sacrificial layer for the air gap
    International Conference on Micro Electro Mechanical Systems, 1998
    Co-Authors: W Kronast, B Muller, W Siedel, A Stoffel
    Abstract:

    A single-chip IC-compatible silicon Condenser Microphone with a highly sensitive silicon nitride membrane and a rigid monocrystalline silicon counterelectrode with acoustic holes was designed and built. Porous silicon with its high dissolution rate in 1% KOH was used as an auxiliary sacrificial layer in combination with sputtered SiO/sub 2/ to define the air gap. This results in low parasitic capacitances and a Microphone structure where the membrane is coplanar with its suspensions. The rigid backelectrode is undistorted, the membrane under low tensile stress, a prerequisite for high sensitivity. Microphones of different dimensions of round and square electrodes with single membranes and membrane arrays were built and packaged in round chip carriers. The open loop sensitivity is in the mV/Pa range depending on the type of Microphone. The frequency response goes beyond 25 kHz for an air gap of 1.3 /spl mu/m.

J. Bergqvist - One of the best experts on this subject based on the ideXlab platform.

  • Capacitive Microphone with a surface micromachined backplate using electroplating technology
    Journal of Microelectromechanical Systems, 1994
    Co-Authors: J. Bergqvist, J. Gobet
    Abstract:

    A technology for surface micromachining of free-standing metal microstructures using metal electrodeposition on a sacrificial photoresist layer has been applied to a Condenser Microphone. Electroplating technology has been used to implement a suspended and perforated 15-/spl mu/m-thick microstructure in copper, which serves as backplate electrode in the Condenser Microphone. The 1.8/spl times/1.8 mm/sup 2/ large Microphone diaphragm is in monocrystalline silicon and is fabricated with anisotropic etching of the substrate wafer. The realized prototypes have a measured sensitivity of 1.4 mV/Pa using a bias voltage of 28 V. The bandwidth is limited by an anti-resonance at 14 kHz which is due to the semi-rigid backplate. The resonance behavior of the backplate structure has been analyzed with finite element modeling with results in good agreement with measured data. >

  • Finite-element modelling and characterization of a silicon Condenser Microphone with a highly perforated backplate
    Sensors and Actuators A: Physical, 1993
    Co-Authors: J. Bergqvist
    Abstract:

    Abstract A new method to simulate the sensitivity and frequency response of capacitive Microphones has been developed. Finite-element analysis is used in combination with equivalent circuits to evaluate mechanical, electrostatic and acoustic effects. The simulation method has been applied to a Condenser Microphone in monocrystalline silicon. The design has a thin and highly perforated backplate in combination with a small air gap of 2 μm. Sensitivities in the range 1–5 mV/Pa have been recorded with a bias voltage between 5 and 13 V. The device has a first resonance at 27 kHz. The measured results are in good agreement with the results obtained with the new simulation method.

  • A silicon Condenser Microphone with a highly perforated backplate
    TRANSDUCERS '91: 1991 International Conference on Solid-State Sensors and Actuators. Digest of Technical Papers, 1
    Co-Authors: J. Bergqvist, F. Rudolf, J. Maisano, F. Parodi, M. Ross
    Abstract:

    Condenser Microphone chips in monocrystalline silicon have been designed and realized with a technology that is well adapted to batch fabrication. The novel design has a thin and highly perforated backplate in combination with an air-gap of 2 mu m. The device has a low bias voltage of 5 V, a frequency response within +or-3 dB from 2 Hz to 20 kHz, and sensitivities in the range of 1 to 2 mV/Pa. Simulations with equivalent acoustical circuits agree well with experimental data up to a frequency of 15 kHz. >

W Kuhnel - One of the best experts on this subject based on the ideXlab platform.

  • a silicon Condenser Microphone with structured back plate and silicon nitride membrane
    Sensors and Actuators A-physical, 1992
    Co-Authors: W Kuhnel, Gisela Hess
    Abstract:

    Abstract The fabrication process of a silicon Condenser Microphone and experimental results of the acoustic measurements are described. The Microphone consists of two chips. One chip carries the 150 nm thick silicon nitride membrane, which has an area of 0.8 mm × 0.8 mm. The second chip contains the back electrode, the spacer and the contact pads of the Microphone. In order to reduce the streaming resistances in the air gap, the back-electrode area is either structured with grooves by a plasma etching technique or with holes by an anisotropic etching technique. A frequency-independent sensitivity of 10 mV/Pa (open circuit, 1.8 mV/Pa measured) up to 30 kHz is obtained as a result of this structuring of the back-electrode area. Since the air-gap height is only 2 μm, the capacitance of the transducers ranges from 1 to 1.3 pF. The total size of the silicon Microphone is 1.6 mm × 2 mm × 0.56 mm.

  • silicon Condenser Microphone with integrated field effect transistor
    Sensors and Actuators A-physical, 1991
    Co-Authors: W Kuhnel
    Abstract:

    Abstract A silicon Condenser Microphone is described, which works with an integrated field-effect transistor (FET). The gate of the transistor corresponds to the membrane of the Microphone. Between the membrane and the gate oxide is a small air gap. The drain current of the transistor is controlled by the deflections of the membrane. The structure, which carries the FET and which is placed beyond the membrane, can have very small lateral dimensions. This results in small values of air-gap streaming losses and high air-gap compliances, thus yielding a good acoustic behaviour. The design of a silicon Microphone with suspended-gate FET is described and experimental results of frequency response and noise are presented. The measured sensitivities are in the range 0.1–1 mV/Pa, which is about 15 dB lower than the calculated values. The reduction in sensitivity is caused by the silicon fabrication process of the Microphones and can be eliminated. The frequency response is smooth up to 30 kHz. The noise measurement shows a 1/ f slope, which is typical for the noise behaviour of the FET.

W Kronast - One of the best experts on this subject based on the ideXlab platform.

  • single chip Condenser Microphone using porous silicon as sacrificial layer for the air gap
    Sensors and Actuators A-physical, 2001
    Co-Authors: W Kronast, B Muller, W Siedel, A Stoffel
    Abstract:

    Abstract A single-chip IC-compatible silicon Condenser Microphone with a highly sensitive silicon nitride diaphragm and a rigid monocrystalline silicon counterelectrode with acoustic holes was designed and built. Porous silicon with its high dissolution rate in 1% KOH was used as an auxiliary sacrificial layer in combination with sputtered SiO 2 to define the air gap. This results in low parasitic capacitances and a Microphone structure where the diaphragm is coplanar with its suspensions. The rigid backelectrode is undistorted, the diaphragm under low tensile stress, a prerequisite for high sensitivity. Microphones of different dimensions of round and square electrodes with single diaphragms and diaphragm arrays were built and packaged in round chip carriers. The open loop sensitivity is in the mV/Pa range depending on the type of Microphone. The frequency response goes beyond 25 kHz for an air gap of 1.3 μm.

  • single chip Condenser Microphone using porous silicon as sacrificial layer for the air gap
    International Conference on Micro Electro Mechanical Systems, 1998
    Co-Authors: W Kronast, B Muller, W Siedel, A Stoffel
    Abstract:

    A single-chip IC-compatible silicon Condenser Microphone with a highly sensitive silicon nitride membrane and a rigid monocrystalline silicon counterelectrode with acoustic holes was designed and built. Porous silicon with its high dissolution rate in 1% KOH was used as an auxiliary sacrificial layer in combination with sputtered SiO/sub 2/ to define the air gap. This results in low parasitic capacitances and a Microphone structure where the membrane is coplanar with its suspensions. The rigid backelectrode is undistorted, the membrane under low tensile stress, a prerequisite for high sensitivity. Microphones of different dimensions of round and square electrodes with single membranes and membrane arrays were built and packaged in round chip carriers. The open loop sensitivity is in the mV/Pa range depending on the type of Microphone. The frequency response goes beyond 25 kHz for an air gap of 1.3 /spl mu/m.