A modified buffered-HF solution with NH4 F ： glycerol ： HF（4 ： 2 ： 1）is studied. With the implementation of a heating and agitating mechanism, this method is applied in a sacrificial layer etching scheme that in...A modified buffered-HF solution with NH4 F ： glycerol ： HF（4 ： 2 ： 1）is studied. With the implementation of a heating and agitating mechanism, this method is applied in a sacrificial layer etching scheme that increases the selectivity between silicon dioxide and aluminum. The etching rates of SiO2 and Al as a function of solution temperature are determined. Moreover,the effects of adding glycerol and agitating the etchant are examined and compared with this method. Finally, this method is tested on an actual device, and its efficiency is scrutinized.展开更多
Traditional MEMS （microelectromechanical system） design methodology is not a structured method and has become an obstacle for MEMS creative design. In this paper, a novel method of mask synthesis and verification fo...Traditional MEMS （microelectromechanical system） design methodology is not a structured method and has become an obstacle for MEMS creative design. In this paper, a novel method of mask synthesis and verification for surface micro-machined MEMS is proposed, which is based on the geometric model of a MEMS device. The emphasis is focused on synthesizing the masks at the basis of the layer model generated from the geometric model of the MEMS device. The method is comprised of several steps： the correction of the layer model, the generation of initial masks and final masks including multi-layer etch masks, and mask simulation. Finally some test resuhs are given.展开更多
Multi-function,multiband,cost-effective,miniaturized reconfigurable radio frequency(RF)components are highly demanded in modern and future wireless communication systems.This paper discusses the needs and implementati...Multi-function,multiband,cost-effective,miniaturized reconfigurable radio frequency(RF)components are highly demanded in modern and future wireless communication systems.This paper discusses the needs and implementation of multiband reconfigurable RF components with microfabrication techniques and advanced materials.RF applications of fabrication methods such as surface and bulk micromachining techniques are reviewed,especially on the development of RF microelectromechanical systems(MEMS)and other tunable components.Works on the application of ferroelectric and ferromagnetic materials are investigated,which enables RF components with continuous tunability,reduced size,and enhanced performance.Methods and strategies with nano-patterning to improve high frequency characteristics of ferromagnetic thin film(e.g.,ferromagnetic resonance frequency and losses)and their applications on the development of fully electrically tunable RF components are fully demonstrated.展开更多
Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,etc.In this study,a novel micro-rolling&incremental sheet formi...Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,etc.In this study,a novel micro-rolling&incremental sheet forming hybrid process(μR-ISF)is proposed to fabricate thin-walled metal parts with microgroove arrays.An analytical model which relates the rolling force and microgroove depth in the micro-rolling stage was first established.Then,the formation mechanism of microgroove morphology during both micro-rolling stage and macro-shape forming stage are investigated.After the micro-grooved sheet being incrementally formed,a significant reduction(between 21%to nearly 60%)is occurred in the depth of both transverse and longitudinal grooves compared to the flat sheet.Meanwhile,the width of transverse grooves decreases slightly by about 10%on average,while the width of longitudinal microgrooves increases significantly by more than 30%on average.After micro-rolling,85°{102}tensile twins appear on the micro-grooved sheet and the percentage of 65°{112}compressive twins increases.After incremental forming,the percentage of low-angle grain boundaries and the density of geometrically necessary dislocations in the formed part increase significantly,and the grain size distribution becomes more uniform.The present work provides a new strategy for the fabrication of 3D metal thin-walled components with surface micro-features.展开更多
A modular and generic monolithic integrated MEMS process for integrating CMOS technology with polysilicon microstructures is presented. The proposed process flow is designed with an intra CMOS approach to fabricate th...A modular and generic monolithic integrated MEMS process for integrating CMOS technology with polysilicon microstructures is presented. The proposed process flow is designed with an intra CMOS approach to fabricate the microstructures into trenches without the need of planarization techniques. After annealing at 1000°C at significant period of time, it is shown that Id-Vg characteristics of the CMOS transistors remain almost unchanged, indicating their robustness to the intra process fabrication for the micromechanical structures. The CMOS module is designed with a 3 μm length as a minimum feature and this process results with a minimum of residual strain and stress on the micromechanical devices (ε = 1.28 × 10<sup>-4</sup> and σ = -21 MPa).展开更多
In this article,a CMOS-compatible Pirani vacuum gauge was proposed featuring enhanced sensitivity,lower detection limit,and high-temperature stability,achieved through the implementation of a surface micromachining me...In this article,a CMOS-compatible Pirani vacuum gauge was proposed featuring enhanced sensitivity,lower detection limit,and high-temperature stability,achieved through the implementation of a surface micromachining method coupled with a temperature compensation strategy.To improve performance,a T-type device with a 1μm gap was fabricated resulting in an average sensitivity of 1.10 V/lgPa,which was 2.89 times larger than that(0.38 V/lgPa)of a L-type device with a 100μm gap.Additionally,FEA simulations were conducted,analyzing the influence of heater temperature on sensitivity and the attenuation of sensitivity across varying ambient temperatures.A semi-empirical theoretical mode was derived for performance prediction,demonstrating strong alignment with experimental results,underscoring its effectiveness in compensating for sensitivity attenuation.Building on the foundation,the device’s performance under different ambient temperatures was characterized and effectively compensated in two distinct operational modes:constant temperature mode and constant temperature difference mode(the whole range temperature compensation error can be controlled within 2.5%).Finally,the short-time stability(variation level is approximately 1 mV),noise floor(Vrms=384μV)and detection limit(0.07 Pa@1 Hz)of the device were characterized,confirming its suitability for practical implementation.展开更多
In this paper, we present the simulation and fabrication of a thin film bulk acoustic resonator （FBAR）. In order to improve the accuracy of simulation, an improved Mason model was introduced to design the resonator ...In this paper, we present the simulation and fabrication of a thin film bulk acoustic resonator （FBAR）. In order to improve the accuracy of simulation, an improved Mason model was introduced to design the resonator by taking the coupling effect between electrode and substrate into consideration. The resonators were fabricated by tile eight inch CMOS process, and the measurements show that the improved Mason model is more accurate than a simple Mason model. The Qs （Q at series resonance）, Qp （Q at parallel resonance）, Qmax and k2 of the FBAR were measured to be 695, 814, 1049, and 7.01% respectively, showing better performace than previous reports.展开更多
基金the National Natural Science Foundation of China(No.50575001)~~
文摘A modified buffered-HF solution with NH4 F ： glycerol ： HF（4 ： 2 ： 1）is studied. With the implementation of a heating and agitating mechanism, this method is applied in a sacrificial layer etching scheme that increases the selectivity between silicon dioxide and aluminum. The etching rates of SiO2 and Al as a function of solution temperature are determined. Moreover,the effects of adding glycerol and agitating the etchant are examined and compared with this method. Finally, this method is tested on an actual device, and its efficiency is scrutinized.
基金Project supported by the National Natural Science Foundation of China (Nos. 60273057 and 60403049) and the National Basic Re-search Program (973) of China (No. 2002CB312106)
文摘Traditional MEMS （microelectromechanical system） design methodology is not a structured method and has become an obstacle for MEMS creative design. In this paper, a novel method of mask synthesis and verification for surface micro-machined MEMS is proposed, which is based on the geometric model of a MEMS device. The emphasis is focused on synthesizing the masks at the basis of the layer model generated from the geometric model of the MEMS device. The method is comprised of several steps： the correction of the layer model, the generation of initial masks and final masks including multi-layer etch masks, and mask simulation. Finally some test resuhs are given.
基金Projects(1253929,1910853)supported by the National Natural Science Foundation of China。
文摘Multi-function,multiband,cost-effective,miniaturized reconfigurable radio frequency(RF)components are highly demanded in modern and future wireless communication systems.This paper discusses the needs and implementation of multiband reconfigurable RF components with microfabrication techniques and advanced materials.RF applications of fabrication methods such as surface and bulk micromachining techniques are reviewed,especially on the development of RF microelectromechanical systems(MEMS)and other tunable components.Works on the application of ferroelectric and ferromagnetic materials are investigated,which enables RF components with continuous tunability,reduced size,and enhanced performance.Methods and strategies with nano-patterning to improve high frequency characteristics of ferromagnetic thin film(e.g.,ferromagnetic resonance frequency and losses)and their applications on the development of fully electrically tunable RF components are fully demonstrated.
基金This work is supported by the National Natural Science Foundation of China(Nos.51975328,52275348)Taishan Scholar Project of Shandong Province(No.tsqn202306006)Youth Innovation Technology Support Program of Shandong Provincial Universities(No.2022KJ041).
文摘Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,etc.In this study,a novel micro-rolling&incremental sheet forming hybrid process(μR-ISF)is proposed to fabricate thin-walled metal parts with microgroove arrays.An analytical model which relates the rolling force and microgroove depth in the micro-rolling stage was first established.Then,the formation mechanism of microgroove morphology during both micro-rolling stage and macro-shape forming stage are investigated.After the micro-grooved sheet being incrementally formed,a significant reduction(between 21%to nearly 60%)is occurred in the depth of both transverse and longitudinal grooves compared to the flat sheet.Meanwhile,the width of transverse grooves decreases slightly by about 10%on average,while the width of longitudinal microgrooves increases significantly by more than 30%on average.After micro-rolling,85°{102}tensile twins appear on the micro-grooved sheet and the percentage of 65°{112}compressive twins increases.After incremental forming,the percentage of low-angle grain boundaries and the density of geometrically necessary dislocations in the formed part increase significantly,and the grain size distribution becomes more uniform.The present work provides a new strategy for the fabrication of 3D metal thin-walled components with surface micro-features.
文摘A modular and generic monolithic integrated MEMS process for integrating CMOS technology with polysilicon microstructures is presented. The proposed process flow is designed with an intra CMOS approach to fabricate the microstructures into trenches without the need of planarization techniques. After annealing at 1000°C at significant period of time, it is shown that Id-Vg characteristics of the CMOS transistors remain almost unchanged, indicating their robustness to the intra process fabrication for the micromechanical structures. The CMOS module is designed with a 3 μm length as a minimum feature and this process results with a minimum of residual strain and stress on the micromechanical devices (ε = 1.28 × 10<sup>-4</sup> and σ = -21 MPa).
基金funded by the National Natural Science Foundation of China(62304023)partially funded by the National Key R&D Program of China(2023YFB3507300)+1 种基金Natural Science Foundation of Chongqing(2022NSCQ-MSX5423)Beijing Institute of Technology Research Fund Program for Young Scholars(XSQD-202206004).
文摘In this article,a CMOS-compatible Pirani vacuum gauge was proposed featuring enhanced sensitivity,lower detection limit,and high-temperature stability,achieved through the implementation of a surface micromachining method coupled with a temperature compensation strategy.To improve performance,a T-type device with a 1μm gap was fabricated resulting in an average sensitivity of 1.10 V/lgPa,which was 2.89 times larger than that(0.38 V/lgPa)of a L-type device with a 100μm gap.Additionally,FEA simulations were conducted,analyzing the influence of heater temperature on sensitivity and the attenuation of sensitivity across varying ambient temperatures.A semi-empirical theoretical mode was derived for performance prediction,demonstrating strong alignment with experimental results,underscoring its effectiveness in compensating for sensitivity attenuation.Building on the foundation,the device’s performance under different ambient temperatures was characterized and effectively compensated in two distinct operational modes:constant temperature mode and constant temperature difference mode(the whole range temperature compensation error can be controlled within 2.5%).Finally,the short-time stability(variation level is approximately 1 mV),noise floor(Vrms=384μV)and detection limit(0.07 Pa@1 Hz)of the device were characterized,confirming its suitability for practical implementation.
基金Project supported by the National Natural Science Foundation of China(Nos.61274119,61306141,61335008)the Natural Science Foundation of Jiangsu Province(No.BK20131099)
文摘In this paper, we present the simulation and fabrication of a thin film bulk acoustic resonator （FBAR）. In order to improve the accuracy of simulation, an improved Mason model was introduced to design the resonator by taking the coupling effect between electrode and substrate into consideration. The resonators were fabricated by tile eight inch CMOS process, and the measurements show that the improved Mason model is more accurate than a simple Mason model. The Qs （Q at series resonance）, Qp （Q at parallel resonance）, Qmax and k2 of the FBAR were measured to be 695, 814, 1049, and 7.01% respectively, showing better performace than previous reports.
