scholarly journals A 0.35-μm CMOS-MEMS Oscillator for High-Resolution Distributed Mass Detection

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 484 ◽  
Author(s):  
Rafel Perelló-Roig ◽  
Jaume Verd ◽  
Joan Barceló ◽  
Sebastià Bota ◽  
Jaume Segura

This paper presents the design, fabrication, and electrical characterization of an electrostatically actuated and capacitive sensed 2-MHz plate resonator structure that exhibits a predicted mass sensitivity of ~250 pg·cm−2·Hz−1. The resonator is embedded in a fully on-chip Pierce oscillator scheme, thus obtaining a quasi-digital output sensor with a short-term frequency stability of 1.2 Hz (0.63 ppm) in air conditions, corresponding to an equivalent mass noise floor as low as 300 pg·cm−2. The monolithic CMOS-MEMS sensor device is fabricated using a commercial 0.35-μm 2-poly-4-metal complementary metal-oxide-semiconductor (CMOS) process, thus featuring low cost, batch production, fast turnaround time, and an easy platform for prototyping distributed mass sensors with unprecedented mass resolution for this kind of devices.

Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 92 ◽  
Author(s):  
Wei-Chun Shen ◽  
Po-Jen Shih ◽  
Yao-Chuan Tsai ◽  
Cheng-Chih Hsu ◽  
Ching-Liang Dai

This study describes the fabrication of an ammonia gas sensor (AGS) using a complementary metal oxide semiconductor (CMOS)–microelectromechanical system (MEMS) technique. The structure of the AGS features interdigitated electrodes (IDEs) and a sensing material on a silicon substrate. The IDEs are the stacked aluminum layers that are made using the CMOS process. The sensing material; polypyrrole/reduced graphene oxide (PPy/RGO), is synthesized using the oxidation–reduction method; and the material is characterized using an electron spectroscope for chemical analysis (ESCA), a scanning electron microscope (SEM), and high-resolution X-ray diffraction (XRD). After the CMOS process; the AGS needs post-processing to etch an oxide layer and to deposit the sensing material. The resistance of the AGS changes when it is exposed to ammonia. A non-inverting amplifier circuit converts the resistance of the AGS into a voltage signal. The AGS operates at room temperature. Experiments show that the AGS response is 4.5% at a concentration of 1 ppm NH3; and it exhibits good repeatability. The lowest concentration that the AGS can detect is 0.1 ppm NH3


Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 722
Author(s):  
Mao ◽  
Yang ◽  
Ma ◽  
Yan ◽  
Zhang

A smart floating gate transistor with two control gates was proposed for active noise control in bioelectrical signal measurement. The device, which is low cost and capable of large-scale integration, was implemented in a standard single-poly complementary metal–oxide–semiconductor (CMOS) process. A model of the device was developed to demonstrate the working principle. Theoretical analysis and simulation results proved the superposition of the two control gates. A series of test experiments were carried out and the results showed that the device was in accordance with the basic electrical characteristics of a floating gate transistor, including the current–voltage (I–V) characteristics and the threshold characteristics observed on the two control gates. Based on the source follower circuit, the experimental results proved that the device can reduce interference by more than 29 dB, which demonstrates the feasibility of the proposed device for active noise control.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Popa ◽  
Richard Hopper ◽  
Syed Zeeshan Ali ◽  
Matthew Thomas Cole ◽  
Ye Fan ◽  
...  

AbstractThe gas sensor market is growing fast, driven by many socioeconomic and industrial factors. Mid-infrared (MIR) gas sensors offer excellent performance for an increasing number of sensing applications in healthcare, smart homes, and the automotive sector. Having access to low-cost, miniaturized, energy efficient light sources is of critical importance for the monolithic integration of MIR sensors. Here, we present an on-chip broadband thermal MIR source fabricated by combining a complementary metal oxide semiconductor (CMOS) micro-hotplate with a dielectric-encapsulated carbon nanotube (CNT) blackbody layer. The micro-hotplate was used during fabrication as a micro-reactor to facilitate high temperature (>700 $$^{\circ }$$ ∘ C) growth of the CNT layer and also for post-growth thermal annealing. We demonstrate, for the first time, stable extended operation in air of devices with a dielectric-encapsulated CNT layer at heater temperatures above 600 $$^{\circ }$$ ∘ C. The demonstrated devices exhibit almost unitary emissivity across the entire MIR spectrum, offering an ideal solution for low-cost, highly-integrated MIR spectroscopy for the Internet of Things.


2021 ◽  
Author(s):  
Daniel Popa ◽  
Richard Hopper ◽  
Syed Zeeshan Ali ◽  
Matthew Cole ◽  
Ye Fan ◽  
...  

Abstract The gas sensor market is growing fast, driven by many socioeconomic and industrial factors. Mid-infrared (MIR) gas sensors offer excellent performance for an increasing number of sensing applications in healthcare, smart homes, and the automotive sector. Having access to low-cost, miniaturized, energy efficient light sources is of critical importance for the monolithic integration of MIR sensors. Here, we present an on-chip broadband thermal MIR source fabricated by combining a complementary metal oxide semiconductor (CMOS) micro-hotplate with a dielectric-encapsulated carbon nanotube (CNT) blackbody layer. The micro-hotplate was used during fabrication as a micro-reactor to facilitate high temperature (>700 • C) growth of the CNT layer and also for post-growth thermal annealing. We demonstrate, for the first time, stable extended operation in air of devices with a dielectric-encapsulated CNT layer at heater temperatures above 600 • C. The demonstrated devices exhibit almost unitary emissivity across the entire MIR spectrum, offering an ideal solution for low-cost, highly-integrated MIR spectroscopy for the Internet of Sensors.


2016 ◽  
Vol 25 (11) ◽  
pp. 1650140 ◽  
Author(s):  
Ling-Feng Shi ◽  
Zhen-Bo Shi ◽  
Sen Chen ◽  
Jian-Hui Xun

Primary-side controlled pulse-width modulation (PWM) flyback converter has been widely used in low-power and low-voltage products for its simple structure and low cost. This paper presents a novel output voltage sampling circuit which considers the influence of the rectifier diode current on the output voltage sampling. The output voltage sampling circuit samples the output voltage at 85% of the secondary inductance discharge time [Formula: see text] of last cycle, which improves the accuracy of the output voltage sampling circuit. Besides, the circuit can also sample the secondary inductance discharge time [Formula: see text]. Finally, a chip has been fabricated in 0.6[Formula: see text][Formula: see text]m complementary metal-oxide semiconductor (CMOS) process, which is used in the presented output voltage sampling circuit in its internal circuit to simple output voltage and achieve constant output voltage.


Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4007 ◽  
Author(s):  
Shu-Jung Chen ◽  
Bin Chen

In this research, a new application of reduced graphene oxide (rGO) for a complementary metal-oxide-semiconductor (CMOS)-MEMS infrared (IR) sensor and emitter is proposed. Thorough investigations of IR properties including absorption and emission were proceeded with careful calibration and measurement with a CMOS thermoelectric sensor. The thermocouples of the sensor consist of aluminum and n-polysilicon layers which are fabricated with the TSMC 0.35 μm CMOS process and MEMS post-process. In order to improve the adhesion of rGO, a sensing area at the center of the membrane is formed with an array of holes, which is easy for the drop-coating of rGO material upon the sensing region. To evaluate the performance of the IR sensor with rGO, different conditions of the IR thermal radiation experiments were arranged. The results show that the responsivity of our proposed CMOS-MEMS IR sensor with rGO increases by about 77% compared with the sensor without rGO. For different IR absorption incident angles, the measurement of field of view shows that the CMOS-MEMS IR sensor with rGO has a smaller view angle, which can be applied for the application of long-distance measuring. In addition, characteristics of the proposed thermopile are estimated and analyzed with comparisons to the available commercial sensors by the experiments.


Instruments ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 33
Author(s):  
Jinsoo Rhim ◽  
Xiaoge Zeng ◽  
Zhihong Huang ◽  
Sai Rahul Chalamalasetti ◽  
Marco Fiorentino ◽  
...  

We present a single-photon sensor based on the single-photon avalanche diode (SPAD) that is suitable for low-cost and low-voltage light detection and ranging (LiDAR) applications. It is implemented in a zero-change standard 0.18-μm complementary metal oxide semiconductor process at the minimum cost by excluding any additional processing step for customized doping profiles. The SPAD is based on circular shaped P+/N-well junction of 8-μm diameter, and it achieves low breakdown voltage below 10 V so that the operation voltage of the single-photon sensor can be minimized. The quenching and reset circuit is integrated monolithically to capture photon-generated output pulses for measurement. A complete characterization of our single-photon sensor is provided.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 800
Author(s):  
Le Yu ◽  
Yaozu Guo ◽  
Haoyu Zhu ◽  
Mingcheng Luo ◽  
Ping Han ◽  
...  

The complementary metal oxide semiconductor (CMOS) microbolometer technology provides a low-cost approach for the long-wave infrared (LWIR) imaging applications. The fabrication of the CMOS-compatible microbolometer infrared focal plane arrays (IRFPAs) is based on the combination of the standard CMOS process and simple post-CMOS micro-electro-mechanical system (MEMS) process. With the technological development, the performance of the commercialized CMOS-compatible microbolometers shows only a small gap with that of the mainstream ones. This paper reviews the basics and recent advances of the CMOS-compatible microbolometer IRFPAs in the aspects of the pixel structure, the read-out integrated circuit (ROIC), the focal plane array, and the vacuum packaging.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 772 ◽  
Author(s):  
Ya-Chu Lee ◽  
Ping-Lin Yang ◽  
Chun-I Chang ◽  
Weileun Fang

This study implements the metal-oxide-semiconductor (MOS) type gas sensor using the TSMC 0.35 μm 2P4M process. The gas concentration is detected based on the resistance change measured by the proposed sensor. This design has three merits: (1) low-cost post-CMOS process using metal/oxide wet etching, (2) composite sensing material based on ZnO-SnO2 coating on the CMOS-MEMS structure, (3) vertical integration of heater and ZnO-SnO2 gas-sensing films using CMOS-MEMS and drop casting technologies. Proposed design significantly increase the sensitivity at the high operating temperature. In summary, the sensitivity of presented sensor increased from 0.04%/% (O2/N2) at near room operating temperature to 0.2%/%(O2/N2) at near 140 °C for the range of 5–50% oxygen concentration.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1272
Author(s):  
Zhihua Fan ◽  
Qinling Deng ◽  
Xiaoyu Ma ◽  
Shaolin Zhou

In recent decades, metasurfaces have emerged as an exotic and appealing group of nanophotonic devices for versatile wave regulation with deep subwavelength thickness facilitating compact integration. However, the ability to dynamically control the wave–matter interaction with external stimulus is highly desirable especially in such scenarios as integrated photonics and optoelectronics, since their performance in amplitude and phase control settle down once manufactured. Currently, available routes to construct active photonic devices include micro-electromechanical system (MEMS), semiconductors, liquid crystal, and phase change materials (PCMs)-integrated hybrid devices, etc. For the sake of compact integration and good compatibility with the mainstream complementary metal oxide semiconductor (CMOS) process for nanofabrication and device integration, the PCMs-based scheme stands out as a viable and promising candidate. Therefore, this review focuses on recent progresses on phase change metasurfaces with dynamic wave control (amplitude and phase or wavefront), and especially outlines those with continuous or quasi-continuous atoms in favor of optoelectronic integration.


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