This study presents recent advances in high-aspect-ratio Deep Reactive Ion Etching (DRIE) of bulk 4H-SiC and thick 4H-SiC on Insulator (SiCOI) substrates at the wafer level. Utilizing an electroplated nickel mask, we successfully achieved high aspect ratios ranging from 10:1 to 18:1 in deep trenches with critical dimensions in the range of 1- $10~mu $ m on the wafer. Trenches having an opening of $sim ~4~mu $ m were etched to greater than the target depth of $45~mu $ m, with a tapering angle of 88.5° and smooth sidewalls (roughness <200nm),> $pm 0.85~mu $ m) across the wafer. These results facilitated batch fabrication of capacitive 4H-SiC bulk acoustic wave disk resonators with high quality factor (Q) approaching 5 million at 3MHz. These achievements in high-aspect-ratio DRIE of 4H-SiC at the wafer level mark a significant stride towards enabling volume manufacturing of ultra-high Q SiC microresonators.[2024-0119]
{"title":"Advances in High-Aspect-Ratio Deep Reactive Ion Etching of 4H-Silicon Carbide Wafers","authors":"Ningxin Li;Zhenming Liu;Ardalan Lotfi;Xinyu Jiang;Emma Long;Shubham S. Sahasrabudhe;Chris Bolton;Huma Ashraf;Farrokh Ayazi","doi":"10.1109/JMEMS.2024.3466769","DOIUrl":"https://doi.org/10.1109/JMEMS.2024.3466769","url":null,"abstract":"This study presents recent advances in high-aspect-ratio Deep Reactive Ion Etching (DRIE) of bulk 4H-SiC and thick 4H-SiC on Insulator (SiCOI) substrates at the wafer level. Utilizing an electroplated nickel mask, we successfully achieved high aspect ratios ranging from 10:1 to 18:1 in deep trenches with critical dimensions in the range of 1-\u0000<inline-formula> <tex-math>$10~mu $ </tex-math></inline-formula>\u0000m on the wafer. Trenches having an opening of \u0000<inline-formula> <tex-math>$sim ~4~mu $ </tex-math></inline-formula>\u0000m were etched to greater than the target depth of \u0000<inline-formula> <tex-math>$45~mu $ </tex-math></inline-formula>\u0000m, with a tapering angle of 88.5° and smooth sidewalls (roughness <200nm),> <tex-math>$pm 0.85~mu $ </tex-math></inline-formula>\u0000m) across the wafer. These results facilitated batch fabrication of capacitive 4H-SiC bulk acoustic wave disk resonators with high quality factor (Q) approaching 5 million at 3MHz. These achievements in high-aspect-ratio DRIE of 4H-SiC at the wafer level mark a significant stride towards enabling volume manufacturing of ultra-high Q SiC microresonators.[2024-0119]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"776-784"},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761424","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}
System-level simulation with macromodel is an important way to help MEMS design and optimization. The applications of traditional MEMS macromodels are confronted with the challenge of incorporating a substantial number of parameters into the macromodel and reconstructing the macromodel when new parameters should be added into the model. To solve the above problem, we propose a novel method for parameterizing macromodels based on modularizing parameters. Firstly, a basic macromodel of a MEMS device with constant hypothetical parameters is constructed. Subsequently, two ways are used to modularize the parameters. The first one is that artificial neural networks (ANNs) are adopted to construct the relationship between non-intuitive parameters with fuzzy behavior and basic macromodel to acquire abstract equations. Another is that the behavioral models of parameters are directly constructed based on behavioral equations for intuitive parameters with clear behavior. Subsequently, a way to implement ANN models by using Verilog-A is also given. Finally, the basic macromodel is assembled with various parameters to obtain the parameterized macromodel of the MEMS device. The highlights of this method are manifested in two aspects. First, ANNs based on data-driven can be applied to various types of parameters, so it has good universality. Second, during the parameterization process, there is no need to reconstruct the basic macromodel. MEMS thermal wind sensor is used to demonstrate the proposed method. The accurate results indicate that this method can provide accurately parameterized macromodels for system-level simulation and has the potential to efficiently support the optimization design of MEMS.[2024-0133]
{"title":"A Novel Parametric System-Level Modeling Method for MEMS Devices Combining Artificial Neural Networks and Behavior Description","authors":"Hao Xu;Lin-Feng Zhao;Zai-Fa Zhou;Zhen-Xiang Yi;Ming Qin;Qing-An Huang","doi":"10.1109/JMEMS.2024.3467126","DOIUrl":"https://doi.org/10.1109/JMEMS.2024.3467126","url":null,"abstract":"System-level simulation with macromodel is an important way to help MEMS design and optimization. The applications of traditional MEMS macromodels are confronted with the challenge of incorporating a substantial number of parameters into the macromodel and reconstructing the macromodel when new parameters should be added into the model. To solve the above problem, we propose a novel method for parameterizing macromodels based on modularizing parameters. Firstly, a basic macromodel of a MEMS device with constant hypothetical parameters is constructed. Subsequently, two ways are used to modularize the parameters. The first one is that artificial neural networks (ANNs) are adopted to construct the relationship between non-intuitive parameters with fuzzy behavior and basic macromodel to acquire abstract equations. Another is that the behavioral models of parameters are directly constructed based on behavioral equations for intuitive parameters with clear behavior. Subsequently, a way to implement ANN models by using Verilog-A is also given. Finally, the basic macromodel is assembled with various parameters to obtain the parameterized macromodel of the MEMS device. The highlights of this method are manifested in two aspects. First, ANNs based on data-driven can be applied to various types of parameters, so it has good universality. Second, during the parameterization process, there is no need to reconstruct the basic macromodel. MEMS thermal wind sensor is used to demonstrate the proposed method. The accurate results indicate that this method can provide accurately parameterized macromodels for system-level simulation and has the potential to efficiently support the optimization design of MEMS.[2024-0133]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"717-728"},"PeriodicalIF":2.5,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761461","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 : 2024-10-04DOI: 10.1109/JMEMS.2024.3465507
Vishnu Kumar;Sudhanshu Tiwari;Gayathri Pillai;Rudra Pratap;Saurabh A. Chandorkar
Piezoelectric microelectromechanical systems have significant market potential owing to their superior capabilities of transduction to those of standard capacitive and piezoresistive devices. However, piezoelectric films are often lossy, which reduces the Quality Factor of devices and affects their performance. It is thus important to examine all sources of energy dissipation in such devices and accurately determine them based on experimental data. Currently used methods to quantify energy dissipation from different sources and the properties of materials based on experimental data are set-up for piezoelectric devices, in which energy storage and dissipation primarily occur in the same piezoelectric material. Moreover, such methods rely on resonance-antiresonance measurements, and thus are unsuitable for thin-film-piezoelectric-on-substrate (TPoS) Micro/Nano devices that have i) a significant portion of energy stored in the substrate/device layer, ii) a low signal-to-noise ratio owing to either lossy piezoelectric films or high motional impedance, or iii) a larger feedthrough capacitance, arising primarily from collocated electrodes, in addition to the internal capacitance of the piezoelectric film. In this paper, we propose a method that overcomes these challenges based on synchronized optical and electrical measurements. We develop a comprehensive physics-based model to extract all the relevant parameters for the device, including the coefficient of piezoelectric coupling, internal and feedthrough capacitance, loss tangents (dielectric, piezoelectric, and mechanical), and the contributions of different sources to the Quality Factor of the device. We showcase the proposed method by using a PZT-based TPoS MEMS cantilever and a Piezoelectric Micromachined Ultrasonic Transducers (PMUT).[2024-0063]
{"title":"Synchronized Opto-Electro-Mechanical Measurements for Estimation of Energy Dissipation in Thin-Film-Piezoelectricon-Substrate MEMS/NEMS Devices","authors":"Vishnu Kumar;Sudhanshu Tiwari;Gayathri Pillai;Rudra Pratap;Saurabh A. Chandorkar","doi":"10.1109/JMEMS.2024.3465507","DOIUrl":"https://doi.org/10.1109/JMEMS.2024.3465507","url":null,"abstract":"Piezoelectric microelectromechanical systems have significant market potential owing to their superior capabilities of transduction to those of standard capacitive and piezoresistive devices. However, piezoelectric films are often lossy, which reduces the Quality Factor of devices and affects their performance. It is thus important to examine all sources of energy dissipation in such devices and accurately determine them based on experimental data. Currently used methods to quantify energy dissipation from different sources and the properties of materials based on experimental data are set-up for piezoelectric devices, in which energy storage and dissipation primarily occur in the same piezoelectric material. Moreover, such methods rely on resonance-antiresonance measurements, and thus are unsuitable for thin-film-piezoelectric-on-substrate (TPoS) Micro/Nano devices that have i) a significant portion of energy stored in the substrate/device layer, ii) a low signal-to-noise ratio owing to either lossy piezoelectric films or high motional impedance, or iii) a larger feedthrough capacitance, arising primarily from collocated electrodes, in addition to the internal capacitance of the piezoelectric film. In this paper, we propose a method that overcomes these challenges based on synchronized optical and electrical measurements. We develop a comprehensive physics-based model to extract all the relevant parameters for the device, including the coefficient of piezoelectric coupling, internal and feedthrough capacitance, loss tangents (dielectric, piezoelectric, and mechanical), and the contributions of different sources to the Quality Factor of the device. We showcase the proposed method by using a PZT-based TPoS MEMS cantilever and a Piezoelectric Micromachined Ultrasonic Transducers (PMUT).[2024-0063]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"793-805"},"PeriodicalIF":2.5,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761469","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 : 2024-10-02DOI: 10.1109/JMEMS.2024.3454944
{"title":"Journal of Microelectromechanical Systems Publication Information","authors":"","doi":"10.1109/JMEMS.2024.3454944","DOIUrl":"https://doi.org/10.1109/JMEMS.2024.3454944","url":null,"abstract":"","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 5","pages":"C2-C2"},"PeriodicalIF":2.5,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10703206","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368335","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 : 2024-10-02DOI: 10.1109/JMEMS.2024.3455088
{"title":"TechRxiv: Share Your Preprint Research with the World!","authors":"","doi":"10.1109/JMEMS.2024.3455088","DOIUrl":"https://doi.org/10.1109/JMEMS.2024.3455088","url":null,"abstract":"","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 5","pages":"656-656"},"PeriodicalIF":2.5,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10703205","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368501","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 : 2024-09-26DOI: 10.1109/JMEMS.2024.3460401
Andrea Buffoli;Marco Gadola;Philippe Robert;Giacomo Langfelder
This document presents a novel architecture of a microelectromechanical system (MEMS) gyroscope for in-plane angular rate sensing (i.e. pitch or roll axis), with a detailed characterization of the performance, including effects of etching nonuniformities and quadrature, which are relevant when dealing with these specific sensing axes. The adopted technology features 20- $mu $ m-thick frames and springs, and 250-nm-thick and -wide resistive gauges, which are subject to stress under Coriolis-force-induced tilt of a torsional lever. The new design increases by a factor larger than 3 the efficiency of the transduction between tilting of the Coriolis frame inside the gyroscope and corresponding stress on the resistive gauges, in turn improving scale-factor, and bringing noise and stability down to record levels for pitch or roll planar silicon micromachined gyroscopes. At the same time, with respect to a former architecture, a comparative analysis of the impact of the new design choices on the dispersion of the mode-split value is carried out. Results demonstrate that the dispersion increases by a negligible amount, from 36 Hz (old design) to 44 Hz (new design). Most of tested gyroscopes have quadrature value within 5000 dps: however, within a 6-V supply operated board, only part of these sensors could be properly operated under automatic quadrature compensation, reaching under these conditions noise in the range of $0.02~^{circ }$ / $surd $ hr and the minimum of the Allan deviation at $0.12~^{circ }$ /hr.[2024-0124]
{"title":"MEMS Pitch Gyroscope Based on (250-nm)² Gauges Achieving 0.12 °/hr Over 1000 dps Full-Scale","authors":"Andrea Buffoli;Marco Gadola;Philippe Robert;Giacomo Langfelder","doi":"10.1109/JMEMS.2024.3460401","DOIUrl":"https://doi.org/10.1109/JMEMS.2024.3460401","url":null,"abstract":"This document presents a novel architecture of a microelectromechanical system (MEMS) gyroscope for in-plane angular rate sensing (i.e. pitch or roll axis), with a detailed characterization of the performance, including effects of etching nonuniformities and quadrature, which are relevant when dealing with these specific sensing axes. The adopted technology features 20-\u0000<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>\u0000m-thick frames and springs, and 250-nm-thick and -wide resistive gauges, which are subject to stress under Coriolis-force-induced tilt of a torsional lever. The new design increases by a factor larger than 3 the efficiency of the transduction between tilting of the Coriolis frame inside the gyroscope and corresponding stress on the resistive gauges, in turn improving scale-factor, and bringing noise and stability down to record levels for pitch or roll planar silicon micromachined gyroscopes. At the same time, with respect to a former architecture, a comparative analysis of the impact of the new design choices on the dispersion of the mode-split value is carried out. Results demonstrate that the dispersion increases by a negligible amount, from 36 Hz (old design) to 44 Hz (new design). Most of tested gyroscopes have quadrature value within 5000 dps: however, within a 6-V supply operated board, only part of these sensors could be properly operated under automatic quadrature compensation, reaching under these conditions noise in the range of \u0000<inline-formula> <tex-math>$0.02~^{circ }$ </tex-math></inline-formula>\u0000/\u0000<inline-formula> <tex-math>$surd $ </tex-math></inline-formula>\u0000hr and the minimum of the Allan deviation at \u0000<inline-formula> <tex-math>$0.12~^{circ }$ </tex-math></inline-formula>\u0000/hr.[2024-0124]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"660-667"},"PeriodicalIF":2.5,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10695088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761465","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}
In this paper, the design, concept and experimental validation of the performances of a piezoelectric resonant microelectromechanical systems (MEMS) phase comparator is presented. Compared to traditional integrated circuits, the potential benefits of a MEMS phase comparator include a low power consumption, higher sensitivity, higher selectivity and improved robustness. The design and experimental validation of a resonant MEMS phase comparator are presented along with characterization recommendations. The operation of this resonant MEMS phase comparator is experimentally validated over the first five eigen modes at 108 kHz, 298.7 kHz, 583.3 kHz, 962.8 kHz and 1.4375 MHz. Calibration of the resonant MEMS phase comparator is presented, allowing for simple device operation, which is validated under various waveform stimulations: sinusoidal, square, and triangular. This work is expected to lead to the development of new applications for MEMS resonating devices. [2024-0037]
{"title":"Design and Experimental Validation of a Piezoelectric Resonant MEMS Phase Comparator","authors":"Mathieu Gratuze;Mohammad Kazemi;Seyedfakhreddin Nabavi;Paul-Vahé Cicek;Alexandre Robichaud;Frederic Nabki","doi":"10.1109/JMEMS.2024.3455106","DOIUrl":"https://doi.org/10.1109/JMEMS.2024.3455106","url":null,"abstract":"In this paper, the design, concept and experimental validation of the performances of a piezoelectric resonant microelectromechanical systems (MEMS) phase comparator is presented. Compared to traditional integrated circuits, the potential benefits of a MEMS phase comparator include a low power consumption, higher sensitivity, higher selectivity and improved robustness. The design and experimental validation of a resonant MEMS phase comparator are presented along with characterization recommendations. The operation of this resonant MEMS phase comparator is experimentally validated over the first five eigen modes at 108 kHz, 298.7 kHz, 583.3 kHz, 962.8 kHz and 1.4375 MHz. Calibration of the resonant MEMS phase comparator is presented, allowing for simple device operation, which is validated under various waveform stimulations: sinusoidal, square, and triangular. This work is expected to lead to the development of new applications for MEMS resonating devices. [2024-0037]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"747-757"},"PeriodicalIF":2.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761496","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 : 2024-09-18DOI: 10.1109/JMEMS.2024.3455095
Roufaida Bensalem;Mohannad Y. Elsayed;Hani H. Tawfik;Mourad N. El-Gamal
This paper presents a novel approach to enhance ultrasound transmission using capacitive micromachined ultrasonic transducers (CMUTs). This is achieved by increasing the cavity height through the use of electrostatic repulsion. Conventional CMUTs based on attractive forces have promising electroacoustic characteristics but limited output pressure, compared to piezoelectric transducers due to the limited motion ranges for CMUTs imposed by the capacitive transduction gap. Therefore, we propose here an electrostatic repulsive CMUT design with three fixed electrodes and one movable electrode that displaces out-of-plane. Simulation results demonstrate the design’s effectiveness in increasing the transducer’s range of motion, thus enhancing transmission sound pressure. Prototypes were fabricated using MEMSCAP’s PolyMUMPs process. Repulsive actuation allows for more than an order of magnitude (11x) improvement in the allowable motion range and therefore an improvement in the acoustic output by a factor up to 25.42 dB. Experimental tests using a vibrometer and an ultrasonic microphone confirm the effectiveness of the proposed approach. The CMUT array operates over a wide band of frequencies from 150 kHz to 650 kHz, which opens the doors for several applications such as ranging, gesture recognition, and non-destructive testing, with the potential for further improvements in ultrasound transmission. [2023-0158]
{"title":"Capacitive Micromachined Transducers With Out-of-Plane Repulsive Actuation for Enhancing Ultrasound Transmission in Air","authors":"Roufaida Bensalem;Mohannad Y. Elsayed;Hani H. Tawfik;Mourad N. El-Gamal","doi":"10.1109/JMEMS.2024.3455095","DOIUrl":"10.1109/JMEMS.2024.3455095","url":null,"abstract":"This paper presents a novel approach to enhance ultrasound transmission using capacitive micromachined ultrasonic transducers (CMUTs). This is achieved by increasing the cavity height through the use of electrostatic repulsion. Conventional CMUTs based on attractive forces have promising electroacoustic characteristics but limited output pressure, compared to piezoelectric transducers due to the limited motion ranges for CMUTs imposed by the capacitive transduction gap. Therefore, we propose here an electrostatic repulsive CMUT design with three fixed electrodes and one movable electrode that displaces out-of-plane. Simulation results demonstrate the design’s effectiveness in increasing the transducer’s range of motion, thus enhancing transmission sound pressure. Prototypes were fabricated using MEMSCAP’s PolyMUMPs process. Repulsive actuation allows for more than an order of magnitude (11x) improvement in the allowable motion range and therefore an improvement in the acoustic output by a factor up to 25.42 dB. Experimental tests using a vibrometer and an ultrasonic microphone confirm the effectiveness of the proposed approach. The CMUT array operates over a wide band of frequencies from 150 kHz to 650 kHz, which opens the doors for several applications such as ranging, gesture recognition, and non-destructive testing, with the potential for further improvements in ultrasound transmission. [2023-0158]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"677-684"},"PeriodicalIF":2.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257829","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}
This paper introduces a novel and simple etching technique that utilizes a mixture of sulfuric acid (H2 SO4) and hydrofluoric acid (HF). This method selectively etches silicon dioxide (SiO2) over aluminum (Al) in Micro-Electro-Mechanical Systems (MEMS) fabrication, offering an alternative to traditional methods that often damage Al or require expensive setups. Here, we employ H2 SO4’s hygroscopic properties to effectively dehydrate HF, reducing water content and limiting fluoride ion generation, which is the cause for Al etching during SiO2 etching. Experimental results demonstrate an exceptional selectivity ratio exceeding 130,000:1 for SiO2 over Al, confirming the method’s precision and the preservation of Al’s integrity. The etching technique preserves the electrical and mechanical properties of Al films, even after extended exposure to the etchant, and demonstrates its effectiveness in the practical fabrication of back-end-of-line (BEOL) micro-electromechanical switches. By utilizing readily available chemicals, the proposed etching method enhances economic feasibility and accessibility, demonstrating significant advancements in MEMS fabrication. The reliability and cost-effectiveness offer a promising solution for integrating microscale structures composed of Al without compromising device performance.[2024-0115]
{"title":"Highly Selective Etching of Silicon Dioxide Over Aluminum Using Mixtures of Sulfuric Acid and Hydrofluoric Acid","authors":"Tae-Soo Kim;Yong-Bok Lee;So-Young Lee;Sung-Ho Kim;Jun-Bo Yoon","doi":"10.1109/JMEMS.2024.3450911","DOIUrl":"10.1109/JMEMS.2024.3450911","url":null,"abstract":"This paper introduces a novel and simple etching technique that utilizes a mixture of sulfuric acid (H2 SO4) and hydrofluoric acid (HF). This method selectively etches silicon dioxide (SiO2) over aluminum (Al) in Micro-Electro-Mechanical Systems (MEMS) fabrication, offering an alternative to traditional methods that often damage Al or require expensive setups. Here, we employ H2 SO4’s hygroscopic properties to effectively dehydrate HF, reducing water content and limiting fluoride ion generation, which is the cause for Al etching during SiO2 etching. Experimental results demonstrate an exceptional selectivity ratio exceeding 130,000:1 for SiO2 over Al, confirming the method’s precision and the preservation of Al’s integrity. The etching technique preserves the electrical and mechanical properties of Al films, even after extended exposure to the etchant, and demonstrates its effectiveness in the practical fabrication of back-end-of-line (BEOL) micro-electromechanical switches. By utilizing readily available chemicals, the proposed etching method enhances economic feasibility and accessibility, demonstrating significant advancements in MEMS fabrication. The reliability and cost-effectiveness offer a promising solution for integrating microscale structures composed of Al without compromising device performance.[2024-0115]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"729-735"},"PeriodicalIF":2.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216961","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 : 2024-08-30DOI: 10.1109/JMEMS.2024.3447694
Satish K. Verma;Bhaskar Mitra
This paper introduces a method for signal amplification and enhancement of full width half maxima (FWHM) in a depletion layer-transduced flexural resonator using the parametric effect. The device can be used as a filter-amplifier, or as a low-noise readout method for sensors. Parametric excitation shows a significant drop in device impedance, from 334.2 k $Omega $ without a pump signal to 45.9 k $Omega $ with a 300 mV pump signal. In the absence of the pump signal, with an input power of −10 dBm, the resonator produces an output power of −44.87 dBm at ~400 kHz and a FWHM value of 23 Hz. However, when a 200 mV pump signal at $2f_{0}$ with $pi $ /2 phase shift, is superimposed with the same input power, the resonator’s output power amplifies to −11.49 dBm, and the FWHM value substantially decreases to 10 Hz. This leads to a 33.58 dBm of amplification and 2.3x improvement in Q attributed to the parametric effect. A detailed analytical model of the transducer is presented. [2024-0061]
本文介绍了一种利用参数效应放大和增强耗尽层换能器全宽半最大值的方法。该装置可以用作滤波放大器，也可以用作传感器的低噪声读出方法。参数激励显示设备阻抗显著下降，从没有泵信号的334.2 k $Omega $到300 mV泵信号的45.9 k $Omega $。在没有泵浦信号的情况下，在输入功率为−10 dBm的情况下，谐振器在400 kHz时产生−44.87 dBm的输出功率，频宽值为23 Hz。然而，当一个200 mV的$2f_{0}$相移$pi $ /2的泵浦信号与相同的输入功率叠加时，谐振器的输出功率放大到- 11.49 dBm， FWHM值大幅降低到10 Hz。这导致33.58 dBm的放大和2.3倍的改进Q归因于参数效应。给出了换能器的详细分析模型。[2024-0061]
{"title":"Parametric Amplification in Depletion Layer Transduced Microelectromechanical Resonator","authors":"Satish K. Verma;Bhaskar Mitra","doi":"10.1109/JMEMS.2024.3447694","DOIUrl":"10.1109/JMEMS.2024.3447694","url":null,"abstract":"This paper introduces a method for signal amplification and enhancement of full width half maxima (FWHM) in a depletion layer-transduced flexural resonator using the parametric effect. The device can be used as a filter-amplifier, or as a low-noise readout method for sensors. Parametric excitation shows a significant drop in device impedance, from 334.2 k\u0000<inline-formula> <tex-math>$Omega $ </tex-math></inline-formula>\u0000 without a pump signal to 45.9 k\u0000<inline-formula> <tex-math>$Omega $ </tex-math></inline-formula>\u0000 with a 300 mV pump signal. In the absence of the pump signal, with an input power of −10 dBm, the resonator produces an output power of −44.87 dBm at ~400 kHz and a FWHM value of 23 Hz. However, when a 200 mV pump signal at \u0000<inline-formula> <tex-math>$2f_{0}$ </tex-math></inline-formula>\u0000 with \u0000<inline-formula> <tex-math>$pi $ </tex-math></inline-formula>\u0000/2 phase shift, is superimposed with the same input power, the resonator’s output power amplifies to −11.49 dBm, and the FWHM value substantially decreases to 10 Hz. This leads to a 33.58 dBm of amplification and 2.3x improvement in Q attributed to the parametric effect. A detailed analytical model of the transducer is presented. [2024-0061]","PeriodicalId":16621,"journal":{"name":"Journal of Microelectromechanical Systems","volume":"33 6","pages":"668-676"},"PeriodicalIF":2.5,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216966","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：