Temperature Compensation of Thermally Actuated, In-Plane Resonant Gas Sensor Using Embedded Oxide-Filled Trenches

Schwartz, Steven A.; Brand, Oliver; Beardslee, Luke A.

doi:10.1109/jmems.2020.3014502

Cited by 8 publications

(4 citation statements)

References 16 publications

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“…To counteract the material softening effects induced by temperature and attain zero TCF1, a variety of temperature compensation strategies-both passive and active-have been employed. Passive methods encompass the utilization of composite materials [12,[15][16][17], high doping concentration [18][19][20][21], and engineered stress profiles [22][23][24], offering the advantage of not necessitating external power sources. Conversely, active compensation techniques, such as electrostatic modulation [9,25,26], phase-locked loops (PLLs) [27,28], and oven control [13,14], typically require external power supplies for operation.…”

Section: Stress-modulated Control Of Tcf and Frequency Shift In 4h-si...mentioning

confidence: 99%

Stress-Modulated Control of TCF and Frequency Shift in 4H-SiC Beam Resonators for Enhanced Thermal Stability

Long,

Liu,

Jiang

et al. 2024

Preprint

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Precision time and frequency references are critical components in electronic devices, impacting sectors such as wireless communications, global positioning systems, and network synchronization. While quartz-based oscillators have historically dominated the market, micro-electromechanical systems (MEMS) resonators are emerging as potential successors, albeit with challenges related to thermal frequency drifts. This paper presents doubly-clamped beam resonators in monocrystalline 4H-silicon carbide (4H-SiC), showcasing a tunable local zero Temperature Coefficient of Frequency (TCF) across a wide temperature range. Our novel approach employs axial stress to counteract temperature-induced softening in the 4H-SiC beam, leveraging the unique attributes of a 4H-SiC on insulator (SiCOI) substrate with a silicon handle layer. By manipulating the beam’s geometrical dimensions, we demonstrate the capability to define the TCF turnover point from -20°C to 100°C and tailor the overall frequency shift. The fabrication process ensures strong covalent interlayer bonds in the 4H-SiCOI substrate, eliminating frequency hysteresis and enhancing yield and stability metrics. We conducted comprehensive short- and long-term stability tests, showing that our resonators exhibit negligible frequency hysteresis across temperature cycles and exceptional long-term stability. Our findings enrich the current understanding of 4H-SiC MEMS resonator thermal stability and pave the way for future innovations in timekeeping and frequency reference technologies. This study underscores the potential of stress-modulated 4H-SiC resonators as reliable, efficient, and versatile instruments for advanced precision timing applications.

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Section: Stress-modulated Control Of Tcf and Frequency Shift In 4h-si...mentioning

confidence: 99%

Stress-Modulated Control of TCF and Frequency Shift in 4H-SiC Beam Resonators for Enhanced Thermal Stability

Long,

Liu,

Jiang

et al. 2024

Preprint

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“…AlN lamb wave resonators with negative TCF can also be temperature compensated by a composite structure [94]. The addition of a layer of SiO 2 underneath the AlN achieved 250 ppm from −55 • C to 125 • C. A MEMS resonant gas sensor with oxide trenches on the edge of the cantilever, which has little degradation to the quality factor, was proposed by [95]. Experimental results show that the proposed design reduces the frequency temperature coefficient to 1.7 ppm/ • C and the quality factor can reach 4700.…”

Section: Passive Compensationmentioning

confidence: 99%

Concepts and Key Technologies of Microelectromechanical Systems Resonators

Feng

Yuan

et al. 2022

Micromachines

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In this paper, the basic concepts of the equivalent model, vibration modes, and conduction mechanisms of MEMS resonators are described. By reviewing the existing representative results, the performance parameters and key technologies, such as quality factor, frequency accuracy, and temperature stability of MEMS resonators, are summarized. Finally, the development status, existing challenges and future trend of MEMS resonators are summarized. As a typical research field of vibration engineering, MEMS resonators have shown great potential to replace quartz resonators in timing, frequency, and resonant sensor applications. However, because of the limitations of practical applications, there are still many aspects of the MEMS resonators that could be improved. This paper aims to provide scientific and technical support for the improvement of MEMS resonators in timing, frequency, and resonant sensor applications.

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“…The results showed that the proposed method was more efficient than the PLL-implemented low-pass filter and achieved a frequency drift of ±8 ppm [ 7 ]. Although some passive compensation methods such as heavily doped silicon or composite materials have been studied [ 8 , 9 , 10 ], it is difficult to achieve the highest stability. The above method only improves the material properties and does not overcome the temperature change.…”

Section: Introductionmentioning

confidence: 99%

A Micro-Hotplate-Based Oven-Controlled System Used to Improve the Frequency Stability of MEMS Resonators

Feng

et al. 2023

Micromachines

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This paper introduces a chip-level oven-controlled system for improving the temperature stability of MEMS resonators wherein we designed the resonator and the micro-hotplate using MEMS technology, then bounding them in a package shell at the chip level. The resonator is transduced by AlN film, and its temperature is monitored by temperature-sensing resistors on both sides. The designed micro-hotplate is placed at the bottom of the resonator chip as a heater and insulated by airgel. The PID pulse width modulation (PWM) circuit controls the heater according to the temperature detection result to provide a constant temperature for the resonator. The proposed oven-controlled MEMS resonator (OCMR) exhibits a frequency drift of 3.5 ppm. Compared with the previously reported similar methods, first, the OCMR structure using airgel combined with a micro-hotplate is proposed for the first time, and the working temperature is extended from 85 °C to 125 °C. Second, our work does not require redesign or additional constraints on the MEMS resonator, so the proposed structure is more general and can be practically applied to other MEMS devices that require temperature control.

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Temperature Compensation of Thermally Actuated, In-Plane Resonant Gas Sensor Using Embedded Oxide-Filled Trenches

Cited by 8 publications

References 16 publications

Stress-Modulated Control of TCF and Frequency Shift in 4H-SiC Beam Resonators for Enhanced Thermal Stability

Stress-Modulated Control of TCF and Frequency Shift in 4H-SiC Beam Resonators for Enhanced Thermal Stability

Concepts and Key Technologies of Microelectromechanical Systems Resonators

A Micro-Hotplate-Based Oven-Controlled System Used to Improve the Frequency Stability of MEMS Resonators

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