The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Yuelin Wang - One of the best experts on this subject based on the ideXlab platform.
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improved Thermopile on pyramidally textured dielectric film
IEEE Electron Device Letters, 2020Co-Authors: Yuelin WangAbstract:In this letter, we pattern thermocouples on the surface of pyramidally-textured dielectric film by careful control of etching and lithography process successfully. Taking advantage of the low thermal conductance and high infrared absorption of the textured dielectric film, the temperature difference between the hot and cold junctions can be increased when this dielectric-film absorber is heated by IR radiation. The fabricated Thermopile with 184 pairs of P+poly-Si/Au thermocouples has responsivity, detectivity, and response time constant of $147.21\pm 4.39\,\,\text{V}\cdot \text{W}\,\,^{{-{1}}},{1.71} \pm {0.04} \times {10}^{{8}}$ cm $\cdot $ Hz $^{\text {1/2}}\cdot \text{W}^{-{1}}$ , and 9.44± 0.25 ms in air, respectively. Compared to the controlled Thermopile based on flat dielectric film, the responsivity and detectivity are significantly improved by more than 58%, while the time constant is still kept less than 10 ms. These results indicate the feasibility of patterning thermocouples on the surface of pyramidally-textured dielectric film for achieving high-performance Thermopiles.
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Performance Enhanced Thermopile With Rough Dielectric Film Black
IEEE Electron Device Letters, 2020Co-Authors: Yunqian He, Yuelin Wang, Tie LiAbstract:In this letter, we report a performance enhanced Thermopile with rough dielectric film black. The pyramidally-textured structure is in-situ formed in the thin dielectric film as an infrared absorber by hard-molding method. Compared to flat dielectric film-based Thermopile with the same size, the output voltage, responsivity, and detectivity of the Thermopile with rough dielectric film black can be improved by approximately 38%, while the response time constant remains less than 10 ms. The pyramidally- textured dielectric film provides a new opportunity to enhance the performance of Thermopiles with the simple process as well as low cost.
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design fabrication and characterization of a high performance cmos compatible Thermopile infrared detector with self test function
Journal of Micromechanics and Microengineering, 2018Co-Authors: Yi Wang, Hong Zhou, Yuelin WangAbstract:This paper presents the design, fabrication and characterization of a CMOS-compatible Thermopile infrared (IR) detector with self-test function based on XeF2 front-side dry etching. In order to achieve better performance, a heavily doped N/P-polysilicon is utilized to form thermocouples, and front-side isotropic etching is adopted to release and thermal isolation. At the same time, a platinum heater on the absorption layer is designed to serve as a heat source to realize the self-test function of the Thermopile IR detector. IR radiation sensing shows that the detector achieves relatively high responsivity of 160.03 V W−1 and detectivity of and a extremely short response time of 2.5 ms in air at room temperature. In addition, a self-test measurement is conducted and validated by applying a voltage to the heater. Compared with traditional methods for detecting Thermopile performance, this method has obvious convenience and simplicity, which provides an effective way for performance monitoring of thermal-based devices.
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research on self test method based on Thermopile infrared sensor
IEEE Sensors, 2018Co-Authors: Yi Wang, Hong Zhou, Yuelin WangAbstract:In this paper, a self-test method is proposed for the Thermopile infrared (IR) detector. To verify the validity of the self-test method, a high-performance Thermopile infrared detector based on XeF2 front-side dry etching is designed, fabricated and characterized. And a platinum heater is fabricated in the absorption area of the Thermopiles to replace the traditional IR radiation to monitor the IR performance of the detector. IR radiation sensing is carried out to characterize the $\mathbf{IR}$ performance of the Thermopile IR detector. The testing results show that the detector achieves a relatively high responsivity of 160.03 V/W and detectivity of $\pmb{9.75\times 10^{7}}$ cm $\mathbf{Hz}^{\pmb{1/2}}\pmb{\cdot \mathrm{W}^{-1}}$ and an extremely short response time of 2.5 ms in the air at room temperature. Moreover, the self-test measurement is conducted by applying a voltage to the heater. Compared with the use of complex equipment such as blackbody and chopper to detect the performance of Thermopile infrared detectors, this method has obvious convenience and simplicity, which provides an effective way for performance monitoring of thermal-based devices.
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A wide measurement pressure range CMOS-MEMS based integrated Thermopile vacuum gauge with an XeF2 dry-etching process
Sensors and Actuators A: Physical, 2013Co-Authors: Xiao Sun, Bin Xiong, Yuelin WangAbstract:Abstract This paper reports a wide pressure measurement range CMOS-MEMS based integrated Thermopile vacuum gauge with an XeF2 dry-etching process. By using XeF2 front-side dry-etching process, a small gap between the suspended heater and the substrate has been obtained, which can extend the upper pressure limit of the gauge. Meanwhile, a small size about 0.4 mm × 1.5 mm of the gauge structure has been obtained, and a good yield of 93% for elements in a wafer has been achieved. A cap mounted on the integrated Thermopile vacuum gauge by wafer level glass frit bonding enhances the gas thermal conduction between the heater and the cap, which increases the sensitivity of the gauge and enlarges the sensing pressure range of the gauge. Moreover, a cap mounted on the gauge provides a chamber to protect the floating integrated Thermopile vacuum gauge structure and a good yield of better than 90% for the packaged integrated Thermopile vacuum gauge has been achieved. The constant power of 4.5 mW is applied to the device, and experimental results show the integrated Thermopile vacuum gauge has a good response to the gas pressure from 5 × 10−3 Pa to 105 Pa.
Jijun Xiong - One of the best experts on this subject based on the ideXlab platform.
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a cmos mems ir device based on double layer thermocouples
Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, 2016Co-Authors: Cheng Lei, Licheng Tang, Wen Ou, Haiyang Mao, Dapeng Chen, Chenyang Xue, Jijun XiongAbstract:In this work, a Thermopile-based MEMS IR sensor is reported. In the device, a double-layer thermocouple strip structure and thermal-conductive-electrical-isolated structures are adopted thus to reduce the size and to improve performance of the whole device. After being packed into a TO-5 package, the sensor achieves a responsivity of 1151.14 V/W, a detectivity of 4.15 × 108 cm Hz1/2/W, and a response time of 14.46 ms. Besides, in measurements of varied temperatures and vacuum pressures, the Thermopile proposed in this work could reach relatively high sensitivities. This indicates that such a device can also function as a temperature sensor and a vacuum sensor. In this way, the applications of Thermopiles are broadened.
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Thermopile infrared detector with detectivity greater than 10 8 cmhz 1 2 w
Journal of Infrared Millimeter and Terahertz Waves, 2010Co-Authors: Kaiqun Wang, Binbin Jiao, Ting Liang, Dapeng Chen, Chenyang Xue, Wendong Zhang, Jijun XiongAbstract:In this paper, the design, fabrication and experimental results of the Thermopile infrared detector, with a single layer of low-stress SiNx membrane, instead of thin sandwich layer membrane of SiO2–Si3N4 are presented. Thermal isolation is achieved by using back etching of bulk silicon. Thermopiles are consisted of serially interconnected p-poly-Si/Al thermocouples supported by the single layer of SiNx membrane with low stress. Au/Ti reflective coating was evaporated on the surface of cold junctions of the Thermopile to block incident radiation. In the measurement, we find that infrared absorbance of SiNx membrane to different wavelength is diverse and less than 100%, which has great influence on calculating the actual absorbing power of the detector, so the infrared (IR) transmission spectrum is measured to calibrate the actual infrared absorbing amount of the detector. The analysis result shows that only 43.72% infrared radiation is absorbed by the detector. Based on the measurement of IR transmission spectrum and output voltage of the detector, the response sensitivity of the detector is calculated as 31.65 V/W, detectivity of the detector is 1.16 × 108 cmHz(1/2)W−1, and response time of the detector is 126 ms.
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micromachined Thermopile infrared detector
2009Co-Authors: Chenyang Xue, Ting Liang, Jijun Xiong, Liu Jun, Yunbo Shi, Wendong Zhang, Kaiqun WangAbstract:The invention relates to the field of an infrared detector, in particular to a micromachined Thermopile infrared detector. The manufacturing technique is simplified and the performance and finished product rate are improved. The manufacture of the micromachined Thermopile infrared detector comprises the following steps of: (1) depositing silicon nitride film on the both sides of a silicon substrate by an LPCVD method; (2) etching to remove peripheral silicon nitride film on the frontal side of the silicon substrate by lithography; (3) manufacturing a plurality of Poly-Si strips both ends of which are respectively arranged on the silicon nitride film and the silicon substrate by LPCVD method and photolithographic process; (4) manufacturing a plurality of aluminum strips which form a thermocouple with the plurality of Poly-Si strips by sputtering and photolithographic processes; (5) depositing the silicon nitride film on the frontal side of the silicon substrate by PECVD method; (6) manufacturing an infrared absorption layer (a carbonized photoresist layer) covering the hot junction area of the Thermopile with photolithographic process; (7) manufacturing a metal reflective layer (a metal layer) covering the cold junction area of the Thermopile with lift-off process; and (8) eroding the back side of the silicon substrate to form a square frustum pyramid shaped groove. The micromachined Thermopile infrared detector has reasonable structure design, simple manufacturing process, high detector performance, high finished product rate, good development prospect and is easy to realize.
Florin Udrea - One of the best experts on this subject based on the ideXlab platform.
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crosstalk analysis of a cmos single membrane Thermopile detector array
Sensors, 2020Co-Authors: Ying Dai, Richard Hopper, Syed Zeeshan Ali, Daniel Popa, Claudio Falco, Prakash Pandey, C H Oxley, Florin UdreaAbstract:We present a new experimental technique to characterise the crosstalk of a Thermopile-based thermal imager, based on bi-directional electrical heating of Thermopile elements. The new technique provides a significantly simpler and more reliable method to determine the crosstalk, compared to a more complex experimental setup with a laser source. The technique is used to characterise a novel single-chip array, fabricated on a single dielectric membrane. We propose a theoretical model to simulate the crosstalk, which shows good agreement with the experimental results. Our results allow a better understanding of the thermal effects in these devices, which are at the center of a rising market of industrial and consumer applications.
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A CMOS-Based Thermopile Array Fabricated on a Single SiO2 Membrane
MDPI AG, 2018Co-Authors: Richard Hopper, Syed Zeeshan Ali, Sophie Boual, Andrea De Luca, Ying Dai, Daniel Popa, Florin UdreaAbstract:We present a novel Thermopile-based infrared (IR) sensor array fabricated on a single CMOS dielectric membrane, comprising of poly-silicon p+ and n+ elements. Processing of the chip is simplified by fabricating the entire array on a single membrane and by using standard CMOS Al metal layers for Thermopile cold junction heatsinking. On a chip area of 1.76 mm × 1.76 mm, with a membrane size of 1.2 mm × 1.2 mm, we fabricated IR sensor arrays with 8 × 8 to 100 × 100 pixels. The 8 × 8 pixel device has <2% thermal crosstalk, a responsivity of 36 V/W and enhanced optical absorption in the 8–14 µm waveband, making it particularly suitable for people presence sensing
Bin Xiong - One of the best experts on this subject based on the ideXlab platform.
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A wide measurement pressure range CMOS-MEMS based integrated Thermopile vacuum gauge with an XeF2 dry-etching process
Sensors and Actuators A: Physical, 2013Co-Authors: Xiao Sun, Bin Xiong, Yuelin WangAbstract:Abstract This paper reports a wide pressure measurement range CMOS-MEMS based integrated Thermopile vacuum gauge with an XeF2 dry-etching process. By using XeF2 front-side dry-etching process, a small gap between the suspended heater and the substrate has been obtained, which can extend the upper pressure limit of the gauge. Meanwhile, a small size about 0.4 mm × 1.5 mm of the gauge structure has been obtained, and a good yield of 93% for elements in a wafer has been achieved. A cap mounted on the integrated Thermopile vacuum gauge by wafer level glass frit bonding enhances the gas thermal conduction between the heater and the cap, which increases the sensitivity of the gauge and enlarges the sensing pressure range of the gauge. Moreover, a cap mounted on the gauge provides a chamber to protect the floating integrated Thermopile vacuum gauge structure and a good yield of better than 90% for the packaged integrated Thermopile vacuum gauge has been achieved. The constant power of 4.5 mW is applied to the device, and experimental results show the integrated Thermopile vacuum gauge has a good response to the gas pressure from 5 × 10−3 Pa to 105 Pa.
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design fabrication and characterization of a front etched micromachined Thermopile for ir detection
Journal of Micromechanics and Microengineering, 2010Co-Authors: Bin Xiong, Yuelin WangAbstract:This paper presents the design, fabrication and experimental results of a front-etched CMOS compatible micromachined Thermopile IR detector. The N-polysilicon/Al thermocouples were embedded in a 2.5 ?m thick SiO2?Si3N4?SiO2 sandwich membrane, and XeF2 front-side isotropic post-etching was adopted to release and thermally isolate the Thermopile structure. Due to the isotropy of XeF2 etching, a lot of flexibility was allowed in etching window layout and Thermopile structure design. Etching windows in the dielectric absorber area were designed to avoid cutting off the heat transfer path from the absorber to hot junctions, and aluminum strips were patterned in the absorber to ensure the temperature was uniform across the absorber area. Two different Thermopile structures, circle and rectangle, were designed and fabricated to investigate detector performance with respect to the Thermopile structure. The steady-state behavior of fabricated detectors was anticipated by thermal ANSYS simulation. Due to the fact that the circular structure can get a higher temperature difference between hot and cold junctions, the circular Thermopile detector has a quicker response, two times higher responsivity and detectivity than the rectangular Thermopile detector. The circular Thermopile detector exhibits a responsivity of 102.0 V W?1, a detectivity of 9.2 ? 107 cm Hz1/2 W?1 and a time constant of 16.8 ms, in air at room temperature.
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integrated micromachined Thermopile ir detectors with an xef2 dry etching process
Journal of Micromechanics and Microengineering, 2009Co-Authors: Bin Xiong, Yuelin Wang, Mifeng LiuAbstract:Based on the Seebeck effect, the CMOS compatible micromachined Thermopile is widely used in infrared detection for its advantages of low-cost, high batch yield, broad spectral response and insensitivity to ambient temperature. We present two integrated Thermopile IR detectors on stacked dielectric layers realized by a standard P-well CMOS technology, followed by one CMOS compatible maskless XeF2 isotropic dry-etching step. Characterizations of CMOS devices, before and after XeF2 etching, respectively, were performed to investigate the effects of XeF2 etching on the CMOS devices. With a 2.5 ?m thick stacked silicon oxide?nitride?oxide layer as an absorber, the rectangular Thermopile detector and the circular Thermopile detector provided responsivity of 14.14 and 10.26 V W?1, specific detectivity of 4.15 ? 107 and 4.54 ? 107 cm Hz1/2 W?1, and time constant of 23.7 and 14.6 ms, respectively. Compared with the rectangular Thermopile detector, the circular Thermopile detector is mechanically more stable, because its circular structure design eases the internal stress problem in the CMOS layers. After XeF2 etching, the maximum changes of threshold voltage, maximum transconductance and switching threshold voltage were 0.97%, 1.25% and 0.08%, respectively. Experimental results show that the effects of XeF2 etching on the CMOS devices are insignificant, and XeF2 etching is suitable for post-CMOS micromachining.
Ken-ichi Uchida - One of the best experts on this subject based on the ideXlab platform.
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Thermopile based on anisotropic magneto peltier effect
Applied Physics Letters, 2019Co-Authors: Raja Das, Ken-ichi UchidaAbstract:We propose Thermopile structures for the anisotropic magneto-Peltier effect (AMPE) to enhance its heating/cooling power. The cross-shaped Thermopile, one of the representative AMPE-based Thermopile structures, consists of four L-shaped ferromagnetic metals arranged in a cross-shaped configuration, which allows the concentration of the AMPE-induced temperature modulation at the center of the cross structure. The AMPE-based Thermopile does not require the use of any complicated junctions comprising different materials, enabling the design of compact and versatile temperature controllers for nanoscale devices.We propose Thermopile structures for the anisotropic magneto-Peltier effect (AMPE) to enhance its heating/cooling power. The cross-shaped Thermopile, one of the representative AMPE-based Thermopile structures, consists of four L-shaped ferromagnetic metals arranged in a cross-shaped configuration, which allows the concentration of the AMPE-induced temperature modulation at the center of the cross structure. The AMPE-based Thermopile does not require the use of any complicated junctions comprising different materials, enabling the design of compact and versatile temperature controllers for nanoscale devices.
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Enhancement of Spin-Seebeck Voltage by Spin-Hall Thermopile
Applied Physics Express, 2012Co-Authors: Ken-ichi Uchida, T. Nonaka, T. Yoshino, Takashi Kikkawa, Daisuke Kikuchi, Eiji SaitohAbstract:Voltage signals induced by the spin-Seebeck effect (SSE) are shown to be enhanced by introducing a Thermopile structure consisting of two different metals with positive and negative spin-Hall angles. In the "spin-Hall Thermopile", the positive and negative SSE signals in the metals are added to the output voltage in series. Here, we demonstrate that a Pt/Nb Thermopile on an Y3Fe5O12 (YIG) slab exhibits the SSE voltage one order of magnitude greater than that in a plain Pt/YIG system. Since the spin-Hall Thermopile enables sensitive detection of a spin voltage in a versatile manner, it will be useful to construct spin and heat sensors.
