Pub Date : 2024-03-18DOI: 10.1109/JMEMS.2023.3337636
Ryan R. Knight;Ryan Q. Rudy;Jeffrey S. Pulskamp;Robert R. Benoit;Don L. DeVoe;Esmond Lau
A quadruple mass Coriolis vibratory gyroscope operating in the mode-matched condition has been redesigned with the singular focus of minimizing nonlinear transduction mechanisms, thereby allowing for angle random walk (ARW) noise reduction when operating at amplitudes higher than $2~mu text{m}$ . This is achieved through the following steps: (i) redesigning the Coriolis mass folded flexures and shuttle springs, (ii) linearizing the antiphase coupler spring rate while maintaining parasitic modal separation, (iii) replacing parallel plate transducers with linear combs, (iv) implementing dedicated force-balanced electrostatic frequency tuners, and (v) microTorr vacuum packaging enabling operation at the thermoelastic dissipation limit of silicon. Additionally, cross-axis stiffness is reduced through folded-flexure moment balancing to further reduce ARW. By the balancing of positive and negative Duffing frequency contributions, net frequency nonlinearity was further reduced to −20 ppm. The gyroscope presented in this study has achieved an ARW of 0.0005 deg/ $surd $ hr, with an uncompensated bias instability of 0.08 deg/hr. These advancements hold promise for enhancing the performance of precision vibratory gyroscopes for navigation and North-finding applications. [2023-0144]
{"title":"Quadruple Mass Gyroscope Angle Random Walk Reduction Through Linearized Transduction","authors":"Ryan R. Knight;Ryan Q. Rudy;Jeffrey S. Pulskamp;Robert R. Benoit;Don L. DeVoe;Esmond Lau","doi":"10.1109/JMEMS.2023.3337636","DOIUrl":"10.1109/JMEMS.2023.3337636","url":null,"abstract":"A quadruple mass Coriolis vibratory gyroscope operating in the mode-matched condition has been redesigned with the singular focus of minimizing nonlinear transduction mechanisms, thereby allowing for angle random walk (ARW) noise reduction when operating at amplitudes higher than \u0000<inline-formula> <tex-math>$2~mu text{m}$ </tex-math></inline-formula>\u0000. This is achieved through the following steps: (i) redesigning the Coriolis mass folded flexures and shuttle springs, (ii) linearizing the antiphase coupler spring rate while maintaining parasitic modal separation, (iii) replacing parallel plate transducers with linear combs, (iv) implementing dedicated force-balanced electrostatic frequency tuners, and (v) microTorr vacuum packaging enabling operation at the thermoelastic dissipation limit of silicon. Additionally, cross-axis stiffness is reduced through folded-flexure moment balancing to further reduce ARW. By the balancing of positive and negative Duffing frequency contributions, net frequency nonlinearity was further reduced to −20 ppm. The gyroscope presented in this study has achieved an ARW of 0.0005 deg/\u0000<inline-formula> <tex-math>$surd $ </tex-math></inline-formula>\u0000hr, with an uncompensated bias instability of 0.08 deg/hr. These advancements hold promise for enhancing the performance of precision vibratory gyroscopes for navigation and North-finding applications. [2023-0144]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 3","pages":"308-321"},"PeriodicalIF":2.7,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this research, micromachined silicon membranes with embedded electrostatic vertical actuator arrays capable of high out-of-plane displacement have been presented. The performance of such devices as MEMS speakers has been characterized by showing relatively high Sound Pressure level (SPL) compared to existing MEMS electrostatic speakers. Large arrays of electrostatic actuator cells, consisting of up to 10,000 cells with submicron transduction gaps, are formed on the edges of the membranes, inducing a bending moment in the membrane upon excitation. The large number of cells, along with submicron transduction gaps, allow much larger vibrational energy to be pumped into the vibrating membrane compared to the conventional electrostatic acoustic transducers, leading to higher sound output. For $50 , mu $ m thick membranes with a device footprint of 5mm $ times 5$ mm, a maximum SPL of 114 dB in open air was measured at a 1 cm distance, translating to an out-of- plane displacement of over $16 , mu $ m for the membrane. The transducer strength figure of merit defined as acoustic pressure per membrane surface area per actuation voltage, for the tested devices, is calculated to be up to $25.1 times 10^{-5}$ Pa/mm2/V, which is over 5X higher than the highest values calculated for the existing art. [2023-0192]
在这项研究中，展示了带有嵌入式静电垂直致动器阵列的微机械硅膜，该阵列能够产生较大的平面外位移。与现有的 MEMS 静电扬声器相比，这种装置作为 MEMS 扬声器的性能表现出相对较高的声压级 (SPL)。由多达 10,000 个具有亚微米传导间隙的单元组成的大型静电致动器单元阵列位于薄膜边缘，在受到激励时会在薄膜上产生弯矩。与传统的静电声学换能器相比，大量的单元和亚微米级的传导间隙可以将更大的振动能量泵入振动膜，从而获得更高的声音输出。对于厚度为 50 mu $ m、设备占地面积为 5 mm 乘以 5 mm 的膜，在 1 cm 距离处测得的开放空气中最大声压级为 114 dB，即膜的平面外位移超过 16 mu $ m。经计算，测试装置的换能器强度优点值（定义为每启动电压下每膜表面积的声压）高达 25.1 times 10^{-5}$ Pa/mm2/V，比现有技术计算出的最高值高出 5 倍多。[2023-0192]
{"title":"Electrostatic MEMS Speakers With Embedded Vertical Actuation","authors":"Md Emran Hossain Bhuiyan;Prithviraj Palit;Siavash Pourkamali","doi":"10.1109/JMEMS.2024.3394809","DOIUrl":"10.1109/JMEMS.2024.3394809","url":null,"abstract":"In this research, micromachined silicon membranes with embedded electrostatic vertical actuator arrays capable of high out-of-plane displacement have been presented. The performance of such devices as MEMS speakers has been characterized by showing relatively high Sound Pressure level (SPL) compared to existing MEMS electrostatic speakers. Large arrays of electrostatic actuator cells, consisting of up to 10,000 cells with submicron transduction gaps, are formed on the edges of the membranes, inducing a bending moment in the membrane upon excitation. The large number of cells, along with submicron transduction gaps, allow much larger vibrational energy to be pumped into the vibrating membrane compared to the conventional electrostatic acoustic transducers, leading to higher sound output. For \u0000<inline-formula> <tex-math>$50 , mu $ </tex-math></inline-formula>\u0000m thick membranes with a device footprint of 5mm \u0000<inline-formula> <tex-math>$ times 5$ </tex-math></inline-formula>\u0000mm, a maximum SPL of 114 dB in open air was measured at a 1 cm distance, translating to an out-of- plane displacement of over \u0000<inline-formula> <tex-math>$16 , mu $ </tex-math></inline-formula>\u0000m for the membrane. The transducer strength figure of merit defined as acoustic pressure per membrane surface area per actuation voltage, for the tested devices, is calculated to be up to \u0000<inline-formula> <tex-math>$25.1 times 10^{-5}$ </tex-math></inline-formula>\u0000 Pa/mm2/V, which is over 5X higher than the highest values calculated for the existing art. [2023-0192]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 4","pages":"446-455"},"PeriodicalIF":2.5,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141061721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a new design for AlScN contour-mode-resonators (CMRs) operating in the radiofrequency (RF) range. This design relies on acoustic metamaterials (AM) based lateral anchors to greatly enhance the power handling compared to conventional CMR-designs. Such anchors generate acoustic stopbands that prevent the leakage of piezo-generated acoustic energy from the resonating body into the substrate. The AM anchors reported in this work consist of the same AlScN film as in the CMRs’ active region, combined with a periodic array of SiO2 rods. Their use allows a reduction of CMRs’ thermal resistance with respect to conventional designs, and enables a significant temperature compensation. As a result, the CMRs with AM anchors reported in this work show a ~60% reduction in their Duffing coefficient with respect to conventional designs with fully-etched lateral sides, hence an improved linearity. Furthermore, when used to set the output frequency of high-power feedback loop oscillators, the CMRs with the AM anchors reported here enable a lower phase-noise compared to what achievable when employing the conventional counterparts.[2024-0053]
{"title":"Multipurpose Acoustic Metamaterial Anchors for Aluminum Scandium Nitride Contour Mode Resonators","authors":"Xuanyi Zhao;Onurcan Kaya;Tommaso Maggioli;Cristian Cassella","doi":"10.1109/JMEMS.2024.3399593","DOIUrl":"10.1109/JMEMS.2024.3399593","url":null,"abstract":"We present a new design for AlScN contour-mode-resonators (CMRs) operating in the radiofrequency (RF) range. This design relies on acoustic metamaterials (AM) based lateral anchors to greatly enhance the power handling compared to conventional CMR-designs. Such anchors generate acoustic stopbands that prevent the leakage of piezo-generated acoustic energy from the resonating body into the substrate. The AM anchors reported in this work consist of the same AlScN film as in the CMRs’ active region, combined with a periodic array of SiO2 rods. Their use allows a reduction of CMRs’ thermal resistance with respect to conventional designs, and enables a significant temperature compensation. As a result, the CMRs with AM anchors reported in this work show a ~60% reduction in their Duffing coefficient with respect to conventional designs with fully-etched lateral sides, hence an improved linearity. Furthermore, when used to set the output frequency of high-power feedback loop oscillators, the CMRs with the AM anchors reported here enable a lower phase-noise compared to what achievable when employing the conventional counterparts.[2024-0053]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 4","pages":"473-481"},"PeriodicalIF":2.5,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10532126","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141063929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1109/JMEMS.2024.3392855
Ethan A. Scott;Hwijong Lee;John N. Nogan;Don Bethke;Peter A. Sharma;Patrick E. Hopkins;Tzu-Ming Lu;C. Thomas Harris
Silicon nitride has long been employed in the microfabrication of thermal sensors due to its favorable material properties and the ease with which it facilitates surface micromachining. While a variety of studies have utilized thin silicon nitride membranes for high sensitivity thermal measurements, limited reports exist on the physical characteristics of membranes and platforms in a thickness limit much less than 100 nm. Herein, we report on the development of low-stress, suspended silicon nitride platform devices that enable thermal characterization of membranes ranging from 120 nm to less than 10 nm in thickness, providing thermal conductivities as low as 1.1 W m−1 K−1 near room temperature. Applications of these platforms may enable appreciable enhancement in the performance of devices reliant upon environmental thermal isolation including bolometers, calorimeters, and gas sensors, among others. [2024-0003]
{"title":"Suspended Silicon Nitride Platforms for Thermal Sensing Applications in the Limit of Minimized Membrane Thickness","authors":"Ethan A. Scott;Hwijong Lee;John N. Nogan;Don Bethke;Peter A. Sharma;Patrick E. Hopkins;Tzu-Ming Lu;C. Thomas Harris","doi":"10.1109/JMEMS.2024.3392855","DOIUrl":"10.1109/JMEMS.2024.3392855","url":null,"abstract":"Silicon nitride has long been employed in the microfabrication of thermal sensors due to its favorable material properties and the ease with which it facilitates surface micromachining. While a variety of studies have utilized thin silicon nitride membranes for high sensitivity thermal measurements, limited reports exist on the physical characteristics of membranes and platforms in a thickness limit much less than 100 nm. Herein, we report on the development of low-stress, suspended silicon nitride platform devices that enable thermal characterization of membranes ranging from 120 nm to less than 10 nm in thickness, providing thermal conductivities as low as 1.1 W m−1 K−1 near room temperature. Applications of these platforms may enable appreciable enhancement in the performance of devices reliant upon environmental thermal isolation including bolometers, calorimeters, and gas sensors, among others. [2024-0003]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 4","pages":"419-426"},"PeriodicalIF":2.5,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141063949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-14DOI: 10.1109/JMEMS.2024.3395294
Lei Zhao;Chong Yang;Xinyue Zhang;Zhiwei You;Yipeng Lu
The demand for high-performance lead-free piezoelectric ultrasound transducers has grown significantly, driven by their applications in implantable, biocompatible medical devices and environmentally friendly consumer electronics. In this study, we present the design, fabrication, and characterization of arrays of lead-free (K, Na)NbO3 (KNN)-based piezoelectric micromechanical ultrasonic transducers (PMUTs) with a center frequency of 4.7 MHz in liquid and 5.85 MHz in air. High-quality KNN thin film (FWHM of 0.32°, $e_{mathrm {31,}f}= -12$ C/m2, $epsilon _{r} =1200$ ) was deposited via physical vapor deposition (PVD) and patterned using an optimized wet etching process with an oxide layer as a mask. Additionally, we obtained a −6 dB fractional bandwidth of 95.7% through optimizing layer stacks and transducers mutual acoustic impedance based on finite element model (FEM) and lumped element model (LEM) methods. We achieved high transmitting performance of 3.8 kPa/V at 3 cm away from a PMUT super-pixel (with an area of 0.278 mm2, consisting of $3times 12$ PMUTs). The measured transducer performance is comparable to previous PMUTs based on PZT (lead-included) thin films and demonstrates the potential of KNN-based PMUTs in future advanced applications. [2024-0005]
{"title":"Design, Fabrication, and Characterization of High-Performance PMUT Arrays Based on Potassium Sodium Niobate","authors":"Lei Zhao;Chong Yang;Xinyue Zhang;Zhiwei You;Yipeng Lu","doi":"10.1109/JMEMS.2024.3395294","DOIUrl":"10.1109/JMEMS.2024.3395294","url":null,"abstract":"The demand for high-performance lead-free piezoelectric ultrasound transducers has grown significantly, driven by their applications in implantable, biocompatible medical devices and environmentally friendly consumer electronics. In this study, we present the design, fabrication, and characterization of arrays of lead-free (K, Na)NbO3 (KNN)-based piezoelectric micromechanical ultrasonic transducers (PMUTs) with a center frequency of 4.7 MHz in liquid and 5.85 MHz in air. High-quality KNN thin film (FWHM of 0.32°, \u0000<inline-formula> <tex-math>$e_{mathrm {31,}f}= -12$ </tex-math></inline-formula>\u0000 C/m2, \u0000<inline-formula> <tex-math>$epsilon _{r} =1200$ </tex-math></inline-formula>\u0000) was deposited via physical vapor deposition (PVD) and patterned using an optimized wet etching process with an oxide layer as a mask. Additionally, we obtained a −6 dB fractional bandwidth of 95.7% through optimizing layer stacks and transducers mutual acoustic impedance based on finite element model (FEM) and lumped element model (LEM) methods. We achieved high transmitting performance of 3.8 kPa/V at 3 cm away from a PMUT super-pixel (with an area of 0.278 mm2, consisting of \u0000<inline-formula> <tex-math>$3times 12$ </tex-math></inline-formula>\u0000 PMUTs). The measured transducer performance is comparable to previous PMUTs based on PZT (lead-included) thin films and demonstrates the potential of KNN-based PMUTs in future advanced applications. [2024-0005]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 4","pages":"438-445"},"PeriodicalIF":2.5,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141061713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-09DOI: 10.1109/JMEMS.2024.3394509
Yufeng Gao;Lei Zhao;Chong Yang;Yipeng Lu
In this paper, we present air-coupled lead-zirconate-titanate (PZT) piezoelectric micromachined ultrasonic transducers (PMUTs) which demonstrate ultra-wide frequency tuning range via controllable in-plane stress generated by DC bias voltage. A PMUT designed to have a resonant frequency of ~200kHz generates a 223kHz total frequency shift from 182.5kHz to 405.5kHz with ±35V DC bias (corresponding to 97.8% variation referring to the resonant frequency without bias), and a 124kHz frequency shift from 188kHz to 312kHz with ±10V DC bias (corresponding to 54.4% variation). The effects of DC bias tuning were further characterized by both impedance analyzer and laser Doppler vibrometer (LDV), the fluctuation of electromechanical coupling coefficient ( ${k}_{mathrm {t}}^{mathrm {2}}$ ) and the change of the direction of polarization of the piezoelectric layer were successfully observed. Frequency tuning along different curves of the hysteresis loop was studied, and given both reasonably good ${k}_{mathrm {t}}^{mathrm {2}}$ (<5%)> $1sim 6$ V DC bias is chosen from the best option of the hysteresis loop. Furthermore, characteristics of PMUTs with different top electrode thickness were studied and summarized, and thinner top electrode was considered as an optimization method to achieve better performance for PMUT under DC bias in terms of frequency tuning. PMUTs with various frequencies were evaluated, and measurement results show a smaller tuning range of PMUTs with higher resonant frequency than those with lower resonant frequency due to the different membrane modulus, and, therefore different contributions of intrinsic stress generated by DC bias to the overall membrane modulus. [2024-0036]
{"title":"Characterization and Optimization of PZT-Based PMUTs With Wide Range Frequency Tuning","authors":"Yufeng Gao;Lei Zhao;Chong Yang;Yipeng Lu","doi":"10.1109/JMEMS.2024.3394509","DOIUrl":"10.1109/JMEMS.2024.3394509","url":null,"abstract":"In this paper, we present air-coupled lead-zirconate-titanate (PZT) piezoelectric micromachined ultrasonic transducers (PMUTs) which demonstrate ultra-wide frequency tuning range via controllable in-plane stress generated by DC bias voltage. A PMUT designed to have a resonant frequency of ~200kHz generates a 223kHz total frequency shift from 182.5kHz to 405.5kHz with ±35V DC bias (corresponding to 97.8% variation referring to the resonant frequency without bias), and a 124kHz frequency shift from 188kHz to 312kHz with ±10V DC bias (corresponding to 54.4% variation). The effects of DC bias tuning were further characterized by both impedance analyzer and laser Doppler vibrometer (LDV), the fluctuation of electromechanical coupling coefficient (\u0000<inline-formula> <tex-math>${k}_{mathrm {t}}^{mathrm {2}}$ </tex-math></inline-formula>\u0000) and the change of the direction of polarization of the piezoelectric layer were successfully observed. Frequency tuning along different curves of the hysteresis loop was studied, and given both reasonably good \u0000<inline-formula> <tex-math>${k}_{mathrm {t}}^{mathrm {2}}$ </tex-math></inline-formula>\u0000 (<5%)> <tex-math>$1sim 6$ </tex-math></inline-formula>\u0000V DC bias is chosen from the best option of the hysteresis loop. Furthermore, characteristics of PMUTs with different top electrode thickness were studied and summarized, and thinner top electrode was considered as an optimization method to achieve better performance for PMUT under DC bias in terms of frequency tuning. PMUTs with various frequencies were evaluated, and measurement results show a smaller tuning range of PMUTs with higher resonant frequency than those with lower resonant frequency due to the different membrane modulus, and, therefore different contributions of intrinsic stress generated by DC bias to the overall membrane modulus. [2024-0036]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 4","pages":"427-437"},"PeriodicalIF":2.5,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140925934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lithium-niobate-on-insulator (LNOI) platform has emerged as a promising solution for fabricating wideband and low-loss surface acoustic wave (SAW) filters. However, it simultaneously excites higher order modes, causing out-of-band (OoB) spurious responses. In this work, the elimination condition for higher order modes in LiNbO3 (LN)/SiO2/poly-Si/Si structure was summarized from analyzing the coupling mechanism between the velocities of shear bulk acoustic waves ( $V_{mathrm {S}}$ ) of Si and that of higher order mode ( $V_{mathrm {p-h}}$ ). According to the elimination condition of $V_{mathrm {p-h}}$ exceeding $V_{mathrm {S}}$ , meticulously selecting the crystal plane and propagation angle $alpha $ of Si to obtain desired $V_{mathrm {S}}$ is necessary. First, the resonators built on $32^{circ }Y$ - $X$ LN/SiO2/poly-Si/Si platforms with typical Si (100), Si (110) and Si (111) substrates were studied by simulation, which reveals that Si (110) manifests the optimal suppression capacity with $alpha _{110}$ window of $18^{circ }-60^{circ }$ , followed by the Si (111) plane of $alpha _{111}= 14^{circ }-36^{circ }$ . Si (100) substrate can hardly suppress higher order modes. Furthermore, resonators were designed and prepared on the above three Si planes. In coherence with the theoretical prediction, the resonators built on Si (135°, 90°, 45°) substrate can effectively eliminate the OoB ripples, while the resonators based on Si (0°, 0°, 45°) and Si (135°, 54.74°, 60°) substrates both excite the higher order modes, whose maximum admittance ratios (AR $_{mathrm {h}}$ ) are 15.0 dB and 19.9 dB, respectively. This work demonstrates a valid methodology for constructing spurious-free filters meeting 5G requirements. [2023-0212]
{"title":"Higher Order Mode Elimination for SAW Resonators Based on LiNbO₃/SiO₂/poly-Si/Si Substrate by Si Orientation Optimization","authors":"Huiping Xu;Sulei Fu;Rongxuan Su;Peisen Liu;Boyuan Xiao;Shuai Zhang;Rui Wang;Cheng Song;Fei Zeng;Weibiao Wang;Feng Pan","doi":"10.1109/JMEMS.2024.3369639","DOIUrl":"10.1109/JMEMS.2024.3369639","url":null,"abstract":"Lithium-niobate-on-insulator (LNOI) platform has emerged as a promising solution for fabricating wideband and low-loss surface acoustic wave (SAW) filters. However, it simultaneously excites higher order modes, causing out-of-band (OoB) spurious responses. In this work, the elimination condition for higher order modes in LiNbO3 (LN)/SiO2/poly-Si/Si structure was summarized from analyzing the coupling mechanism between the velocities of shear bulk acoustic waves (\u0000<inline-formula> <tex-math>$V_{mathrm {S}}$ </tex-math></inline-formula>\u0000) of Si and that of higher order mode (\u0000<inline-formula> <tex-math>$V_{mathrm {p-h}}$ </tex-math></inline-formula>\u0000). According to the elimination condition of \u0000<inline-formula> <tex-math>$V_{mathrm {p-h}}$ </tex-math></inline-formula>\u0000 exceeding \u0000<inline-formula> <tex-math>$V_{mathrm {S}}$ </tex-math></inline-formula>\u0000, meticulously selecting the crystal plane and propagation angle \u0000<inline-formula> <tex-math>$alpha $ </tex-math></inline-formula>\u0000 of Si to obtain desired \u0000<inline-formula> <tex-math>$V_{mathrm {S}}$ </tex-math></inline-formula>\u0000 is necessary. First, the resonators built on \u0000<inline-formula> <tex-math>$32^{circ }Y$ </tex-math></inline-formula>\u0000-\u0000<inline-formula> <tex-math>$X$ </tex-math></inline-formula>\u0000 LN/SiO2/poly-Si/Si platforms with typical Si (100), Si (110) and Si (111) substrates were studied by simulation, which reveals that Si (110) manifests the optimal suppression capacity with \u0000<inline-formula> <tex-math>$alpha _{110}$ </tex-math></inline-formula>\u0000 window of \u0000<inline-formula> <tex-math>$18^{circ }-60^{circ }$ </tex-math></inline-formula>\u0000, followed by the Si (111) plane of \u0000<inline-formula> <tex-math>$alpha _{111}= 14^{circ }-36^{circ }$ </tex-math></inline-formula>\u0000. Si (100) substrate can hardly suppress higher order modes. Furthermore, resonators were designed and prepared on the above three Si planes. In coherence with the theoretical prediction, the resonators built on Si (135°, 90°, 45°) substrate can effectively eliminate the OoB ripples, while the resonators based on Si (0°, 0°, 45°) and Si (135°, 54.74°, 60°) substrates both excite the higher order modes, whose maximum admittance ratios (AR\u0000<inline-formula> <tex-math>$_{mathrm {h}}$ </tex-math></inline-formula>\u0000) are 15.0 dB and 19.9 dB, respectively. This work demonstrates a valid methodology for constructing spurious-free filters meeting 5G requirements. [2023-0212]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 2","pages":"163-173"},"PeriodicalIF":2.7,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140072791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-07DOI: 10.1109/JMEMS.2024.3371829
Almur A. S. Rabih;Seyedfakhreddin Nabavi;Michaël Ménard;Frederic Nabki
This article proposes an electrothermal three-degrees-of-freedom (3-DOF) micro-positioner equipped with a waveguide path, which can potentially be used for chip-to-chip alignment in photonic integrated circuits. The micro-positioner provides translational displacements along the x-, y- and z- axes with manageable levels of cross-sensitivity between axes. A fabricated prototype provides displacements of $pm 3.35~mu text{m}$ at 105 mW along the x-axis, and $+4.5~mu text{m}$ at 140 mW along the y-axis. Moreover, $+7~mu text{m}$ of out-of-plane displacement is achieved along the z-axis when 210 mW is applied to the x-axis actuators to buckle the structure. The AC response of the micro-positioner shows that the fundamental resonance mode occurs at 18.8 kHz. [2023-0208]
本文提出了一种配备波导路径的电热三自由度（3-DOF）微型定位器，可用于光子集成电路中芯片到芯片的对准。该微型定位器沿 x、y 和 z 轴提供平移位移，各轴之间的交叉灵敏度在可控范围内。制造出的原型在 105 mW 的功率下可沿 x 轴提供 $pm 3.35~mu text{m}$，在 140 mW 的功率下可沿 y 轴提供 $+4.5~mu text{m}$。此外，当对 x 轴致动器施加 210 mW 以扣合结构时，沿 z 轴可实现 $+7~mu text{m}$的平面外位移。微型定位器的交流响应显示，基本共振模式发生在 18.8 kHz。[2023-0208]
{"title":"A 3 Degrees-of-Freedom Electrothermal Micro-Positioner for Optical Chip-to-Chip Alignment","authors":"Almur A. S. Rabih;Seyedfakhreddin Nabavi;Michaël Ménard;Frederic Nabki","doi":"10.1109/JMEMS.2024.3371829","DOIUrl":"10.1109/JMEMS.2024.3371829","url":null,"abstract":"This article proposes an electrothermal three-degrees-of-freedom (3-DOF) micro-positioner equipped with a waveguide path, which can potentially be used for chip-to-chip alignment in photonic integrated circuits. The micro-positioner provides translational displacements along the x-, y- and z- axes with manageable levels of cross-sensitivity between axes. A fabricated prototype provides displacements of \u0000<inline-formula> <tex-math>$pm 3.35~mu text{m}$ </tex-math></inline-formula>\u0000 at 105 mW along the x-axis, and \u0000<inline-formula> <tex-math>$+4.5~mu text{m}$ </tex-math></inline-formula>\u0000 at 140 mW along the y-axis. Moreover, \u0000<inline-formula> <tex-math>$+7~mu text{m}$ </tex-math></inline-formula>\u0000 of out-of-plane displacement is achieved along the z-axis when 210 mW is applied to the x-axis actuators to buckle the structure. The AC response of the micro-positioner shows that the fundamental resonance mode occurs at 18.8 kHz. [2023-0208]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 2","pages":"260-273"},"PeriodicalIF":2.7,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140072152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-05DOI: 10.1109/JMEMS.2024.3360460
Xiaoyan Sun;Haikuan Chen;Zhouwei He;Haoning Zheng;Ji’an Duan;Youwang Hu
This paper reports a method to optimize the structure of a hemispherical shell resonator by reducing the thermoelastic dissipation. In accordance with the thermoelastic damping theory, we set up a thermal insulation structure to change the heat conduction distance to improve the thermoelastic quality factor. And according to the distribution of elastic strain energy on the resonator, we set up the thermal insulating cavities and thermal insulating layers at the top and rim of the resonator to change the heat conduction distance, respectively. The vibration characteristics of the four new resonators are compared with the conventional resonator by finite element calculation, and the new structural resonators are fabricated with the optimal parameter. We measured that the quality factor ( $Q$ -factor) of the optimized resonator was improved by 13.8 times than that of the original structural resonator. It is also found that by adjusting the insulation structure, not only the thermoelastic quality factor of the resonator can be improved, but also the modal frequency of the resonator can be adjusted, which is able to realize the fine control of the vibration characteristics of the resonator. [2023-0168]
{"title":"Optimization of Hemispherical Shell Resonator Structure Based on Thermoelastic Dissipation","authors":"Xiaoyan Sun;Haikuan Chen;Zhouwei He;Haoning Zheng;Ji’an Duan;Youwang Hu","doi":"10.1109/JMEMS.2024.3360460","DOIUrl":"10.1109/JMEMS.2024.3360460","url":null,"abstract":"This paper reports a method to optimize the structure of a hemispherical shell resonator by reducing the thermoelastic dissipation. In accordance with the thermoelastic damping theory, we set up a thermal insulation structure to change the heat conduction distance to improve the thermoelastic quality factor. And according to the distribution of elastic strain energy on the resonator, we set up the thermal insulating cavities and thermal insulating layers at the top and rim of the resonator to change the heat conduction distance, respectively. The vibration characteristics of the four new resonators are compared with the conventional resonator by finite element calculation, and the new structural resonators are fabricated with the optimal parameter. We measured that the quality factor (\u0000<inline-formula> <tex-math>$Q$ </tex-math></inline-formula>\u0000-factor) of the optimized resonator was improved by 13.8 times than that of the original structural resonator. It is also found that by adjusting the insulation structure, not only the thermoelastic quality factor of the resonator can be improved, but also the modal frequency of the resonator can be adjusted, which is able to realize the fine control of the vibration characteristics of the resonator. [2023-0168]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 2","pages":"133-142"},"PeriodicalIF":2.7,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140043917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We studied the temperature effects on the resonant frequency of nano piezoelectric mechanical resonators based on Hf0.5Zr0.5O2 thin films. Two square-shaped resonators of 30 $mu$ m and 50 $mu$ m in length were fabricated and tested, having a resonant frequency of 225.8 kHz and 98.5 kHz, respectively. The temperature coefficient of frequency (TCF) of the devices was characterized in the range from −20 °C to 147 °C. Both devices exhibited a positive TCF around 83.6 ppm/°C to 105 ppm/°C in the range from 30 °C to 147 °C, which may result from the combined effect of thermal expansion mismatch between the materials and the temperature coefficient of Young’s modulus of the HZO material. Moreover, the 50 $mu$ m device shows a negative TCF around −110 ppm/°C to −99.9 ppm/°C within the range from −20 °C to 30 °C, which may be due to stress relaxation during the heating process. These results underscore the significance of HZO material in nanoscale piezoelectric resonator applications and lay the foundation for our future work aimed at developing nanoscale piezoelectric devices based on HZO. [2024-0040]
{"title":"Characterization of a Temperature-Sensitive Nano Piezoelectric Mechanical Resonator With a 20nm Free-Standing Hf0.5Zr0.5O2 Membrane","authors":"Jingyi Zhang;Haoqi Lyu;Wuhao Yang;Hai Zhong;Zhuohui Liu;Xiaorui Bie;Xingyin Xiong;Zheng Wang;Chen Ge;Xudong Zou","doi":"10.1109/JMEMS.2024.3392402","DOIUrl":"10.1109/JMEMS.2024.3392402","url":null,"abstract":"We studied the temperature effects on the resonant frequency of nano piezoelectric mechanical resonators based on Hf0.5Zr0.5O2 thin films. Two square-shaped resonators of 30 \u0000<inline-formula> <tex-math>$mu$ </tex-math></inline-formula>\u0000 m and 50 \u0000<inline-formula> <tex-math>$mu$ </tex-math></inline-formula>\u0000 m in length were fabricated and tested, having a resonant frequency of 225.8 kHz and 98.5 kHz, respectively. The temperature coefficient of frequency (TCF) of the devices was characterized in the range from −20 °C to 147 °C. Both devices exhibited a positive TCF around 83.6 ppm/°C to 105 ppm/°C in the range from 30 °C to 147 °C, which may result from the combined effect of thermal expansion mismatch between the materials and the temperature coefficient of Young’s modulus of the HZO material. Moreover, the 50 \u0000<inline-formula> <tex-math>$mu$ </tex-math></inline-formula>\u0000 m device shows a negative TCF around −110 ppm/°C to −99.9 ppm/°C within the range from −20 °C to 30 °C, which may be due to stress relaxation during the heating process. These results underscore the significance of HZO material in nanoscale piezoelectric resonator applications and lay the foundation for our future work aimed at developing nanoscale piezoelectric devices based on HZO. [2024-0040]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 4","pages":"405-407"},"PeriodicalIF":2.5,"publicationDate":"2024-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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