Epitaxial graphene grown on silicon carbide(Si C/graphene)is a promising solution for achieving a highprecision quantum Hall resistance standard.Previous research mainly focused on the quantum resistance metrology of ...Epitaxial graphene grown on silicon carbide(Si C/graphene)is a promising solution for achieving a highprecision quantum Hall resistance standard.Previous research mainly focused on the quantum resistance metrology of n-type Si C/graphene,while a comprehensive understanding of the quantum resistance metrology behavior of graphene with different doping types is lacking.Here,we fabricated both n-and p-type Si C/graphene devices via polymer-assisted molecular adsorption and conducted systematic magneto-transport measurements in a wide parameter space of carrier density and temperature.It is demonstrated that n-type devices show greater potential for development of quantum resistance metrology compared with p-type devices,as evidenced by their higher carrier mobility,lower critical magnetic field for entering quantized Hall plateaus,and higher robustness of the quantum Hall effect against thermal degeneration.These discrepancies can be reasonably attributed to the weaker scattering from molecular dopants for n-type devices,which is further supported by the analyses on the quantum interference effect in multiple devices.These results enrich our understanding of the charged impurity on electronic transport performance of graphene and,more importantly,provide a useful reference for future development of graphene-based quantum resistance metrology.展开更多
To professionally plan and manage the development and evolution of the Internet of Things(IoT),researchers have proposed several IoT performance measurement solutions.IoT performance measurement solutions can be very ...To professionally plan and manage the development and evolution of the Internet of Things(IoT),researchers have proposed several IoT performance measurement solutions.IoT performance measurement solutions can be very valuable for managing the development and evolution of IoT systems,as they provide insights into performance issues,resource optimization,predictive maintenance,security,reliability,and user experience.However,there are several issues that can impact the accuracy and reliability of IoT performance measurements,including lack of standardization,complexity of IoT systems,scalability,data privacy,and security.While previous studies proposed several IoT measurement solutions in the literature,they did not evaluate any individual one to figure out their respective measurement strengths and weaknesses.This study provides a novel scheme for the evaluation of proposed IoT measurement solutions using a metrology-coverage evaluation based on evaluation theory,metrology principles,and software measurement best practices.This evaluation approach was employed for 12 IoT measure categories and 158 IoT measurement solutions identified in a Systematic Literature Review(SLR)from 2010 to 2021.The metrology coverage of these IoT measurement solutions was analyzed from four perspectives:across IoT categories,within each study,improvement over time,and implications for IoT practitioners and researchers.The criteria in this metrology-coverage evaluation allowed for the identification of strengths and weaknesses in the theoretical and empirical definitions of the proposed IoT measurement solutions.We found that the metrological coverage varies significantly across IoT measurement solution categories and did not show improvement over the 2010–2021 timeframe.Detailed findings can help practitioners understand the limitations of the proposed measurement solutions and choose those with stronger designs.These evaluation results can also be used by researchers to improve current IoT measurement solution designs and suggest new solutions with a stronger metrology base.展开更多
The paper tackles the problem of reading singularities of the geomagnetic field in noisy underwater (UW) environments. In particular, we propose a novel metrological approach to measuring low-amplitude geomagnetic sig...The paper tackles the problem of reading singularities of the geomagnetic field in noisy underwater (UW) environments. In particular, we propose a novel metrological approach to measuring low-amplitude geomagnetic signals in hard noisy magnetic environments. This research action was launched to develop a detection system for enforcing the peripheral security of military bases (harbors/coasts and landbases) and for asymmetric warfare. The concept underlying this theory is the spatial stability in the temporal variations of the geomagnetic field in the observation area. The paper presents the development and deployment of a self-informed measurement system, in which the signal acquired from each sensor—observation node—is compared with the signal acquired by the adjacent ones. The effectiveness of this procedure relates to the inter-node (sensor-to-sensor) distance, L;this quantity should, on one hand, correlate the noise and, on the other hand, decorrelate the target signal. The paper presents the results obtained, that demonstrate the ability of self-informed systems to read weak magnetic signals even in the presence of very high noise in low-density ionic solutions (i.e. sea water).展开更多
Automation in measurement has wide range of electrical metrology applications and construction of powerful calibration software is one of the highly accurate metrological laboratories’ priorities. Thus, two automatic...Automation in measurement has wide range of electrical metrology applications and construction of powerful calibration software is one of the highly accurate metrological laboratories’ priorities. Thus, two automatic systems for controlling and calibrating the electrical reference standards have been established at National Institute for Standards (NIS), Egypt. The first system has been built to calibrate the zener diode reference standards while the second one has been built to calibrate the electrical sourcing and measuring instruments. These two systems act as the comprehensive and reliable structure that, from the national electrical standards, disseminates the traceability to all the electrical units under calibration. The software of the two systems has been built using the Laboratory Virtual Instrument Engineering Workbench (LabVIEW) graphical language. The standard development procedures have been followed in the building of both systems software. The software requirement specifications as well as functional specifications are taken into consideration. Design, implementation and testing of the software have been performed. Furthermore, software validation for measurements’ uncertainty as well as results’ compatibility in both automatic and manual modes has been achieved.展开更多
3D NAND technical development and manufacturing face many challenges to scale down their devices,and metrology stands out as much more difficult at each turn.Unlike planar NAND,3D NAND has a three-dimensional vertical...3D NAND technical development and manufacturing face many challenges to scale down their devices,and metrology stands out as much more difficult at each turn.Unlike planar NAND,3D NAND has a three-dimensional vertical structure with high-aspect ratio.Obviously top-down images is not enough for process control,instead inner structure control becomes much more important than before,e.g.channel hole profiles.Besides,multi-layers,special materials and YMTC unique X-Tacking technology also bring other metrology challenges:high wafer bow,stress induced overlay,opaque film measurement.Technical development can adopt some destructive methodology(TEM,etch-back SEM),while manufacturing can only use nondestructive method.These drive some new metrology development,including X-Ray,mass measure and Mid-IR spectroscopy.As 3D NAND suppliers move to>150 layers devices,the existing metrology tools will be pushed to the limits.Still,the metrology must innovate.展开更多
The dynamics of the quantum Fisher information(QFI) of phase parameter estimation in a non-Markovian dissipative qubit system is investigated within the structure of single and double Lorentzian spectra. We use the ti...The dynamics of the quantum Fisher information(QFI) of phase parameter estimation in a non-Markovian dissipative qubit system is investigated within the structure of single and double Lorentzian spectra. We use the time-convolutionless method with fourth-order perturbation expansion to obtain the general forms of QFI for the qubit system in terms of a non-Markovian master equation. We find that the phase parameter estimation can be enhanced in our model within both single and double Lorentzian spectra. What is more, the detuning and spectral width are two significant factors affecting the enhancement of parameter-estimation precision.展开更多
We investigate the advantage of coherent superposition of two different coded channels in quantum metrology.In a continuous variable system,we show that the Heisenberg limit 1/N can be beaten by the coherent superposi...We investigate the advantage of coherent superposition of two different coded channels in quantum metrology.In a continuous variable system,we show that the Heisenberg limit 1/N can be beaten by the coherent superposition without the help of indefinite causal order.And in parameter estimation,we demonstrate that the strategy with the coherent superposition can perform better than the strategy with quantum switch which can generate indefinite causal order.We analytically obtain the general form of estimation precision in terms of the quantum Fisher information and further prove that the nonlinear Hamiltonian can improve the estimation precision and make the measurement uncertainty scale as 1/N^(m) for m≥2.Our results can help to construct a high-precision measurement equipment,which can be applied to the detection of coupling strength and the test of time dilation and the modification of the canonical commutation relation.展开更多
The frictional properties of micro bearings have strong influence on the performance of the whole system because of tiny scale of micro-electromechanical system (MEMS). To develop micro bearings with low friction,it i...The frictional properties of micro bearings have strong influence on the performance of the whole system because of tiny scale of micro-electromechanical system (MEMS). To develop micro bearings with low friction,it is important to evaluate the friction behaviors on the micro bearing. The testing system and the principle to evaluate the tribological performance of micromachining work-pieces under the load of mill Newton scale is introduced in paper "A new approach to measure the friction coefficient of micro journal bearings" of Yao et al,. But as the tribological force is faint in micro scale, the measured force is influenced a lot by the testing error. As the equation of that of Yao’s paper is very sensitive to the measured force, the tested result is influenced remarkably by testing error. So it is hard to get precision result. To solve this problem, the test system with new compensation method is introduced to precisely evaluate tribological performance under mill scale. The new metrology method is developed by means of the error compensation from two sets of testing data. The data are the force collected respectively when the friction counterparts rotate in CW(clockwise) and CCW(counter-clockwise) direction. So we deduce the equation of friction coefficient respctively on the condition of journal running in CCW and CW direction. As condition of measuring those two friciton coefficients are alike except the running direction of journal, and then the friction coefficient should be the same because this difference of direction has no influence on the fricition coefficients. Considering this, we unite the both equation, make the data measured in different subtract each other in the equation, and then a new equation can be gotten. This new equation enhances the metrology precision of friction coefficient theoretically thanks to the counteracting of error values in the equation. Using this method we testing the friction of high speed steel journal with hard alloy bearing. The result shows the new compensation method has better precision and repetition than CW and CCW method thanks to the error resistance.展开更多
Laser-driven light sources(LDLS)have ultrahigh-brightness and broad wavelength range.They are ideal radiation sources for optical metrology tools for advanced process control in semiconductor manufacturing.LDLS source...Laser-driven light sources(LDLS)have ultrahigh-brightness and broad wavelength range.They are ideal radiation sources for optical metrology tools for advanced process control in semiconductor manufacturing.LDLS sources,with their advantages of 170 nm to 2100 nm wavelength range,have been widely adopted and are being used in volume manufacturing for spectroscopic ellipsometry(SE),spectroscopic scatterometry(SS),and white light interferometry(WLI)applications.Such applications are used to measure critical dimensions(CD),overlay(OVL),and film thickness.展开更多
3D NAND(three-dimensional NAND type)has rapidly become the standard technology for enterprise flash memories,and is also gaining widespread use in other applications.Continued manufacturing process improvements are es...3D NAND(three-dimensional NAND type)has rapidly become the standard technology for enterprise flash memories,and is also gaining widespread use in other applications.Continued manufacturing process improvements are essential in delivering memory devices with higher I/O performance,higher bit density,and at lower cost.Current 3D NAND technology involves process steps that form array and peripheral CMOS(Complementary Metal-Oxide-Semiconductor)regions side-by-side,resulting in waste of silicon real estate and film stress compromises,and limits the paths of making advanced 3D NAND devices.An innovative architecture was invented to overcome these challenges by connecting two wafers electrically through metal VIAs(Vertical Interconnect Access)[1].Highly accurate and efficient metrology is required to monitor VIA interface due to increased process complexity and precision requirements.With the advanced processing of AFM(Atomic Force Microscopy)images,highly accurate and precise measurements have been achieved.An inline pattern-centric metrology solution that is designed for high volume mass production of high-performance 3D NAND is presented in this paper.展开更多
Pursuing small critical dimensions(i.e.14 nm or below)and high integration bring us lots of physical defects causing low yield and functionality failures for foundries.Under this circumstance,inspection,metrology and ...Pursuing small critical dimensions(i.e.14 nm or below)and high integration bring us lots of physical defects causing low yield and functionality failures for foundries.Under this circumstance,inspection,metrology and monitoring technologies are unprecedentedly vital for development of semiconductor industry.Optical and electron beam solutions are the most common two methods in semiconductor manufacturing.Hamamatsu Photonics is now aiming at optical inspection,metrology and monitoring systems market by providing light sources,photodetectors and failure analysis systems for semiconductor equipment manufacturers,foundries and research institutions.In this paper,features and potential applications of light sources,photodetectors(like image sensors,photomultiplier tubes/modules,silicon photomultipliers(modules),(avalanche)photodiodes(arrays)and so on),with the wavelengths ranging from UV to Infrared,are mainly discussed.In addition,Hamamatsu’s star product– failure analysis system to quickly locate faults or defects are introduced.In conclusion,Hamamatsu Photonics is dedicated to develop large varieties of light sources and optical sensors/detector/modules along with failure analysis systems and willing to improve the development of semiconductor and related industries,especially in China.展开更多
In traditional 3D NAND design,peripheral circuit accounts for 20-30%of the chip realestate,which reduces the memory density of flash memory.As 3D NAND technology stacks to 128 layers or higher,peripheral circuits may ...In traditional 3D NAND design,peripheral circuit accounts for 20-30%of the chip realestate,which reduces the memory density of flash memory.As 3D NAND technology stacks to 128 layers or higher,peripheral circuits may account for more than 50%of the overall chip area.On the contrast,the Xtacking^TM technology arranges array and logic parts on two different wafers,and connects the memory arrays to the logic circuit by metal VIAs(Vertical Interconnect Accesses)to achieve unprecedented high storage density as well as DRAM level I/O speed.As a consequence,it becomes increasingly significant to monitor metal VIAs depth before wafer bonding process as to ensure reliability of array-logic connections.Currently,AFM(Atom Force Microscopy)is the main stream method of VIA depth monitoring.Apparently,AFM wins the battle of precision,however the low throughput limited its usage in mass production.In order to accomplish the requirement of VLSI production,a WLI(White Light Interference)metrology is revisited and a novel WLI method was developed to monitor VIAs depth.Basically there are two major limitations that keep WLI tools from wider use,transparent film impact and diffraction limitation.In this work,the engineering solutions are illustrated and inline dishing measurement is achieved with high accuracy and precision.展开更多
May 20 is World Metrology Day and the theme of this year is 'Metrology and Energy Conservation.' Energy is not only a vital issue for China, but also for the world. In order to implement Proposal of the CP... May 20 is World Metrology Day and the theme of this year is 'Metrology and Energy Conservation.' Energy is not only a vital issue for China, but also for the world. In order to implement Proposal of the CPC Central Committee on the 11th Five-Year Program for National Economic and Social Development, the government bulletin of 5th Plenary Session of the 16th CPC Central Committee announced that 'there shall be marked improvement on resource utilization; the energy consumption for unit GDP shall cut 20%, water consumption of unit industrial added value drop 30%... and the recycle ratio of industrial solid wastes shall raise by 60%.' These are key targets of economic development during the 11th five-year program. To make full use of metrology for energy conservation and energy utilization, the competent metrology department of Chinese Goyernment advanced metrology program in light of China's energy status.……展开更多
The theme of this year’s World Metrology Day is “Metrology and Energy”. The energy problem is an important issue for the whole world and has received great attention in China since China is both a big energy-consum...The theme of this year’s World Metrology Day is “Metrology and Energy”. The energy problem is an important issue for the whole world and has received great attention in China since China is both a big energy-consuming country and a country severely short of energy. Under the energy and environmental pressure,China will take measures in the following four respects in order to solve the problem of energy展开更多
Recently the National Petroleum Products Quality Supervision and Inspection Center(NPPQIC)affiliated to the SINOPEC Research Institute of Petroleum Processing(RIPP)has been approved by the China National Certification...Recently the National Petroleum Products Quality Supervision and Inspection Center(NPPQIC)affiliated to the SINOPEC Research Institute of Petroleum Processing(RIPP)has been approved by the China National Certification and Accreditation Administration(CNCA)and has obtained the expanded qualification recognition of China Metrology Accreditation(CMA).展开更多
The optical frequency comb serves as a powerful tool for distance measurement by integrating numerous stable optical modes into interferometric measurements,enabling unprecedented absolute measurement precision.Noneth...The optical frequency comb serves as a powerful tool for distance measurement by integrating numerous stable optical modes into interferometric measurements,enabling unprecedented absolute measurement precision.Nonetheless,due to the periodicity of its pulse train,the comb suffers from measurement dead zones and ambiguities,thereby impeding its practical applications.Here,we present a linear group delay spectral interferometer for achieving precise full-range distance measurements.By employing a carefully designed linear group delay(LGD)device for phase modulation of the comb modes,interference can occur and be easily measured at any position.Our approach effectively eliminates the dead zones and ambiguities in comb-based ranging,without the need for cumbersome auxiliary scanning reference devices or reliance on complex high-repetition-rate combs or high-resolution spectrometers.We conducted length metrology experiments using a mode-locked comb referenced to a rubidium clock,achieving a large nonambiguity range up to 0.3 m,covering the entire measurement period.The maximum deviation compared to a laser interferometer was less than 1.5μm,and the minimum Allan deviation during long-term measurements reached 5.47 nm at a 500 s averaging time.The approach ensures high accuracy while maintaining a simple structure,without relying on complex external devices,thereby propelling the practical implementation of comb-based length metrology.展开更多
Because quantum critical systems are very sensitive to the variation of parameters around the quantum phase transition(QPT),quantum criticality has been presented as an efficient resource for metrology.In this paper,w...Because quantum critical systems are very sensitive to the variation of parameters around the quantum phase transition(QPT),quantum criticality has been presented as an efficient resource for metrology.In this paper,we address the issue whether the divergent feature of the inverted variance is realizable in the presence of noise when approaching the QPT.Taking the quantum Rabi model(QRM)as an example,we obtain the analytical result for the inverted variance with single-photon relaxation.We show that the inverted variance may be convergent in time due to the noise.Since the precision of the metrology is very sensitive to the noise,as a remedy,we propose squeezing the initial state to improve the precision under decoherence.In addition,we also investigate the criticality-based metrology under the influence of the two-photon relaxation.Strikingly,although the maximum inverted variance still manifests a power-law dependence on the energy gap,the exponent is positive and depends on the dimensionless coupling strength.This observation implies that the criticality may not enhance but weaken the precision in the presence of two-photon relaxation,due to the non-linearity introduced by the twophoton relaxation.展开更多
Overlay(OVL)for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process.The tolerance of OVL metrology for the latest microchip needs to be at nan...Overlay(OVL)for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process.The tolerance of OVL metrology for the latest microchip needs to be at nanometer scale.This paper discusses the influence on the accuracy and sensitivity of diffraction-based overlay(DBO)after developing inspection and after etching inspection by the asymmetrical deformation of the OVL mark induced by chemical mechanical polishing or etching.We show that the accuracy and sensitivity of DBO metrology can be significantly improved by matching the measuring light wavelength to the thickness between layers and by collecting high-order diffraction signals,promising a solution for future OVL metrology equipment.展开更多
基金supported by the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-046)the National Natural Science Foundation of China(Grant Nos.92165201,11974324,12104435)+4 种基金the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)the Anhui Initiative in Quantum Information Technologies(Grant No.AHY170000)Hefei Science Center CAS(Grant No.2020HSC-UE014)the Fundamental Research Funds for the Central Universities(Grant Nos.WK3510000013 and WK2310000104)supported by USTC Tang Scholar。
文摘Epitaxial graphene grown on silicon carbide(Si C/graphene)is a promising solution for achieving a highprecision quantum Hall resistance standard.Previous research mainly focused on the quantum resistance metrology of n-type Si C/graphene,while a comprehensive understanding of the quantum resistance metrology behavior of graphene with different doping types is lacking.Here,we fabricated both n-and p-type Si C/graphene devices via polymer-assisted molecular adsorption and conducted systematic magneto-transport measurements in a wide parameter space of carrier density and temperature.It is demonstrated that n-type devices show greater potential for development of quantum resistance metrology compared with p-type devices,as evidenced by their higher carrier mobility,lower critical magnetic field for entering quantized Hall plateaus,and higher robustness of the quantum Hall effect against thermal degeneration.These discrepancies can be reasonably attributed to the weaker scattering from molecular dopants for n-type devices,which is further supported by the analyses on the quantum interference effect in multiple devices.These results enrich our understanding of the charged impurity on electronic transport performance of graphene and,more importantly,provide a useful reference for future development of graphene-based quantum resistance metrology.
基金supported by the University of South Africa under Grant No.409000.
文摘To professionally plan and manage the development and evolution of the Internet of Things(IoT),researchers have proposed several IoT performance measurement solutions.IoT performance measurement solutions can be very valuable for managing the development and evolution of IoT systems,as they provide insights into performance issues,resource optimization,predictive maintenance,security,reliability,and user experience.However,there are several issues that can impact the accuracy and reliability of IoT performance measurements,including lack of standardization,complexity of IoT systems,scalability,data privacy,and security.While previous studies proposed several IoT measurement solutions in the literature,they did not evaluate any individual one to figure out their respective measurement strengths and weaknesses.This study provides a novel scheme for the evaluation of proposed IoT measurement solutions using a metrology-coverage evaluation based on evaluation theory,metrology principles,and software measurement best practices.This evaluation approach was employed for 12 IoT measure categories and 158 IoT measurement solutions identified in a Systematic Literature Review(SLR)from 2010 to 2021.The metrology coverage of these IoT measurement solutions was analyzed from four perspectives:across IoT categories,within each study,improvement over time,and implications for IoT practitioners and researchers.The criteria in this metrology-coverage evaluation allowed for the identification of strengths and weaknesses in the theoretical and empirical definitions of the proposed IoT measurement solutions.We found that the metrological coverage varies significantly across IoT measurement solution categories and did not show improvement over the 2010–2021 timeframe.Detailed findings can help practitioners understand the limitations of the proposed measurement solutions and choose those with stronger designs.These evaluation results can also be used by researchers to improve current IoT measurement solution designs and suggest new solutions with a stronger metrology base.
文摘The paper tackles the problem of reading singularities of the geomagnetic field in noisy underwater (UW) environments. In particular, we propose a novel metrological approach to measuring low-amplitude geomagnetic signals in hard noisy magnetic environments. This research action was launched to develop a detection system for enforcing the peripheral security of military bases (harbors/coasts and landbases) and for asymmetric warfare. The concept underlying this theory is the spatial stability in the temporal variations of the geomagnetic field in the observation area. The paper presents the development and deployment of a self-informed measurement system, in which the signal acquired from each sensor—observation node—is compared with the signal acquired by the adjacent ones. The effectiveness of this procedure relates to the inter-node (sensor-to-sensor) distance, L;this quantity should, on one hand, correlate the noise and, on the other hand, decorrelate the target signal. The paper presents the results obtained, that demonstrate the ability of self-informed systems to read weak magnetic signals even in the presence of very high noise in low-density ionic solutions (i.e. sea water).
文摘Automation in measurement has wide range of electrical metrology applications and construction of powerful calibration software is one of the highly accurate metrological laboratories’ priorities. Thus, two automatic systems for controlling and calibrating the electrical reference standards have been established at National Institute for Standards (NIS), Egypt. The first system has been built to calibrate the zener diode reference standards while the second one has been built to calibrate the electrical sourcing and measuring instruments. These two systems act as the comprehensive and reliable structure that, from the national electrical standards, disseminates the traceability to all the electrical units under calibration. The software of the two systems has been built using the Laboratory Virtual Instrument Engineering Workbench (LabVIEW) graphical language. The standard development procedures have been followed in the building of both systems software. The software requirement specifications as well as functional specifications are taken into consideration. Design, implementation and testing of the software have been performed. Furthermore, software validation for measurements’ uncertainty as well as results’ compatibility in both automatic and manual modes has been achieved.
基金The authors would like to thank all YMTC metrology vendors for helping with tool evaluation,data collection and data analysis.
文摘3D NAND technical development and manufacturing face many challenges to scale down their devices,and metrology stands out as much more difficult at each turn.Unlike planar NAND,3D NAND has a three-dimensional vertical structure with high-aspect ratio.Obviously top-down images is not enough for process control,instead inner structure control becomes much more important than before,e.g.channel hole profiles.Besides,multi-layers,special materials and YMTC unique X-Tacking technology also bring other metrology challenges:high wafer bow,stress induced overlay,opaque film measurement.Technical development can adopt some destructive methodology(TEM,etch-back SEM),while manufacturing can only use nondestructive method.These drive some new metrology development,including X-Ray,mass measure and Mid-IR spectroscopy.As 3D NAND suppliers move to>150 layers devices,the existing metrology tools will be pushed to the limits.Still,the metrology must innovate.
基金Projects supported by the Natural Science Foundation of Guangdong Province,China(Grant No.2015A030310354)the Science Foundation for Enhancing School with Innovation of Guangdong Ocean University(Grant Nos.GDOU2017052504 and GDOU2015050207)+1 种基金the Foundation of Excellent-YoungBackbone Teacher of Guangdong Ocean University(Grant No.HDYQ2017005)the Fund of University Student Innovation and Entrepreneurship Team of Guangdong Ocean University(Grant No.CCTD201823)
文摘The dynamics of the quantum Fisher information(QFI) of phase parameter estimation in a non-Markovian dissipative qubit system is investigated within the structure of single and double Lorentzian spectra. We use the time-convolutionless method with fourth-order perturbation expansion to obtain the general forms of QFI for the qubit system in terms of a non-Markovian master equation. We find that the phase parameter estimation can be enhanced in our model within both single and double Lorentzian spectra. What is more, the detuning and spectral width are two significant factors affecting the enhancement of parameter-estimation precision.
基金Project supported by the National Natural Science Foundation of China(Grant No.62001134)the Natural Science Foundation of Guangxi Zhuang Autonomous Region,China(Grant No.2020GXNSFAA159047)the National Key Research and Development Program of China(Grant No.2018YFB1601402-2).
文摘We investigate the advantage of coherent superposition of two different coded channels in quantum metrology.In a continuous variable system,we show that the Heisenberg limit 1/N can be beaten by the coherent superposition without the help of indefinite causal order.And in parameter estimation,we demonstrate that the strategy with the coherent superposition can perform better than the strategy with quantum switch which can generate indefinite causal order.We analytically obtain the general form of estimation precision in terms of the quantum Fisher information and further prove that the nonlinear Hamiltonian can improve the estimation precision and make the measurement uncertainty scale as 1/N^(m) for m≥2.Our results can help to construct a high-precision measurement equipment,which can be applied to the detection of coupling strength and the test of time dilation and the modification of the canonical commutation relation.
文摘The frictional properties of micro bearings have strong influence on the performance of the whole system because of tiny scale of micro-electromechanical system (MEMS). To develop micro bearings with low friction,it is important to evaluate the friction behaviors on the micro bearing. The testing system and the principle to evaluate the tribological performance of micromachining work-pieces under the load of mill Newton scale is introduced in paper "A new approach to measure the friction coefficient of micro journal bearings" of Yao et al,. But as the tribological force is faint in micro scale, the measured force is influenced a lot by the testing error. As the equation of that of Yao’s paper is very sensitive to the measured force, the tested result is influenced remarkably by testing error. So it is hard to get precision result. To solve this problem, the test system with new compensation method is introduced to precisely evaluate tribological performance under mill scale. The new metrology method is developed by means of the error compensation from two sets of testing data. The data are the force collected respectively when the friction counterparts rotate in CW(clockwise) and CCW(counter-clockwise) direction. So we deduce the equation of friction coefficient respctively on the condition of journal running in CCW and CW direction. As condition of measuring those two friciton coefficients are alike except the running direction of journal, and then the friction coefficient should be the same because this difference of direction has no influence on the fricition coefficients. Considering this, we unite the both equation, make the data measured in different subtract each other in the equation, and then a new equation can be gotten. This new equation enhances the metrology precision of friction coefficient theoretically thanks to the counteracting of error values in the equation. Using this method we testing the friction of high speed steel journal with hard alloy bearing. The result shows the new compensation method has better precision and repetition than CW and CCW method thanks to the error resistance.
文摘Laser-driven light sources(LDLS)have ultrahigh-brightness and broad wavelength range.They are ideal radiation sources for optical metrology tools for advanced process control in semiconductor manufacturing.LDLS sources,with their advantages of 170 nm to 2100 nm wavelength range,have been widely adopted and are being used in volume manufacturing for spectroscopic ellipsometry(SE),spectroscopic scatterometry(SS),and white light interferometry(WLI)applications.Such applications are used to measure critical dimensions(CD),overlay(OVL),and film thickness.
文摘3D NAND(three-dimensional NAND type)has rapidly become the standard technology for enterprise flash memories,and is also gaining widespread use in other applications.Continued manufacturing process improvements are essential in delivering memory devices with higher I/O performance,higher bit density,and at lower cost.Current 3D NAND technology involves process steps that form array and peripheral CMOS(Complementary Metal-Oxide-Semiconductor)regions side-by-side,resulting in waste of silicon real estate and film stress compromises,and limits the paths of making advanced 3D NAND devices.An innovative architecture was invented to overcome these challenges by connecting two wafers electrically through metal VIAs(Vertical Interconnect Access)[1].Highly accurate and efficient metrology is required to monitor VIA interface due to increased process complexity and precision requirements.With the advanced processing of AFM(Atomic Force Microscopy)images,highly accurate and precise measurements have been achieved.An inline pattern-centric metrology solution that is designed for high volume mass production of high-performance 3D NAND is presented in this paper.
文摘Pursuing small critical dimensions(i.e.14 nm or below)and high integration bring us lots of physical defects causing low yield and functionality failures for foundries.Under this circumstance,inspection,metrology and monitoring technologies are unprecedentedly vital for development of semiconductor industry.Optical and electron beam solutions are the most common two methods in semiconductor manufacturing.Hamamatsu Photonics is now aiming at optical inspection,metrology and monitoring systems market by providing light sources,photodetectors and failure analysis systems for semiconductor equipment manufacturers,foundries and research institutions.In this paper,features and potential applications of light sources,photodetectors(like image sensors,photomultiplier tubes/modules,silicon photomultipliers(modules),(avalanche)photodiodes(arrays)and so on),with the wavelengths ranging from UV to Infrared,are mainly discussed.In addition,Hamamatsu’s star product– failure analysis system to quickly locate faults or defects are introduced.In conclusion,Hamamatsu Photonics is dedicated to develop large varieties of light sources and optical sensors/detector/modules along with failure analysis systems and willing to improve the development of semiconductor and related industries,especially in China.
文摘In traditional 3D NAND design,peripheral circuit accounts for 20-30%of the chip realestate,which reduces the memory density of flash memory.As 3D NAND technology stacks to 128 layers or higher,peripheral circuits may account for more than 50%of the overall chip area.On the contrast,the Xtacking^TM technology arranges array and logic parts on two different wafers,and connects the memory arrays to the logic circuit by metal VIAs(Vertical Interconnect Accesses)to achieve unprecedented high storage density as well as DRAM level I/O speed.As a consequence,it becomes increasingly significant to monitor metal VIAs depth before wafer bonding process as to ensure reliability of array-logic connections.Currently,AFM(Atom Force Microscopy)is the main stream method of VIA depth monitoring.Apparently,AFM wins the battle of precision,however the low throughput limited its usage in mass production.In order to accomplish the requirement of VLSI production,a WLI(White Light Interference)metrology is revisited and a novel WLI method was developed to monitor VIAs depth.Basically there are two major limitations that keep WLI tools from wider use,transparent film impact and diffraction limitation.In this work,the engineering solutions are illustrated and inline dishing measurement is achieved with high accuracy and precision.
文摘 May 20 is World Metrology Day and the theme of this year is 'Metrology and Energy Conservation.' Energy is not only a vital issue for China, but also for the world. In order to implement Proposal of the CPC Central Committee on the 11th Five-Year Program for National Economic and Social Development, the government bulletin of 5th Plenary Session of the 16th CPC Central Committee announced that 'there shall be marked improvement on resource utilization; the energy consumption for unit GDP shall cut 20%, water consumption of unit industrial added value drop 30%... and the recycle ratio of industrial solid wastes shall raise by 60%.' These are key targets of economic development during the 11th five-year program. To make full use of metrology for energy conservation and energy utilization, the competent metrology department of Chinese Goyernment advanced metrology program in light of China's energy status.……
文摘The theme of this year’s World Metrology Day is “Metrology and Energy”. The energy problem is an important issue for the whole world and has received great attention in China since China is both a big energy-consuming country and a country severely short of energy. Under the energy and environmental pressure,China will take measures in the following four respects in order to solve the problem of energy
文摘Recently the National Petroleum Products Quality Supervision and Inspection Center(NPPQIC)affiliated to the SINOPEC Research Institute of Petroleum Processing(RIPP)has been approved by the China National Certification and Accreditation Administration(CNCA)and has obtained the expanded qualification recognition of China Metrology Accreditation(CMA).
基金National Natural Science Foundation of China(62205036)National Key Research and Development Program of China(2023YFF0715701)+1 种基金China Postdoctoral Science Foundation(2021M700614)Chongqing Natural Science Foundation(cstc2021jcyj-bsh X0083)。
文摘The optical frequency comb serves as a powerful tool for distance measurement by integrating numerous stable optical modes into interferometric measurements,enabling unprecedented absolute measurement precision.Nonetheless,due to the periodicity of its pulse train,the comb suffers from measurement dead zones and ambiguities,thereby impeding its practical applications.Here,we present a linear group delay spectral interferometer for achieving precise full-range distance measurements.By employing a carefully designed linear group delay(LGD)device for phase modulation of the comb modes,interference can occur and be easily measured at any position.Our approach effectively eliminates the dead zones and ambiguities in comb-based ranging,without the need for cumbersome auxiliary scanning reference devices or reliance on complex high-repetition-rate combs or high-resolution spectrometers.We conducted length metrology experiments using a mode-locked comb referenced to a rubidium clock,achieving a large nonambiguity range up to 0.3 m,covering the entire measurement period.The maximum deviation compared to a laser interferometer was less than 1.5μm,and the minimum Allan deviation during long-term measurements reached 5.47 nm at a 500 s averaging time.The approach ensures high accuracy while maintaining a simple structure,without relying on complex external devices,thereby propelling the practical implementation of comb-based length metrology.
基金supported by Beijing Natural Science Foundation under Grant No.1202017the National Natural Science Foundation of China under Grant Nos.11674033 and 11505007Beijing Normal University under Grant No.2022129.
文摘Because quantum critical systems are very sensitive to the variation of parameters around the quantum phase transition(QPT),quantum criticality has been presented as an efficient resource for metrology.In this paper,we address the issue whether the divergent feature of the inverted variance is realizable in the presence of noise when approaching the QPT.Taking the quantum Rabi model(QRM)as an example,we obtain the analytical result for the inverted variance with single-photon relaxation.We show that the inverted variance may be convergent in time due to the noise.Since the precision of the metrology is very sensitive to the noise,as a remedy,we propose squeezing the initial state to improve the precision under decoherence.In addition,we also investigate the criticality-based metrology under the influence of the two-photon relaxation.Strikingly,although the maximum inverted variance still manifests a power-law dependence on the energy gap,the exponent is positive and depends on the dimensionless coupling strength.This observation implies that the criticality may not enhance but weaken the precision in the presence of two-photon relaxation,due to the non-linearity introduced by the twophoton relaxation.
基金supported by the Science and Technology Commission of Shanghai Municipality(No.22DZ1100300)。
文摘Overlay(OVL)for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process.The tolerance of OVL metrology for the latest microchip needs to be at nanometer scale.This paper discusses the influence on the accuracy and sensitivity of diffraction-based overlay(DBO)after developing inspection and after etching inspection by the asymmetrical deformation of the OVL mark induced by chemical mechanical polishing or etching.We show that the accuracy and sensitivity of DBO metrology can be significantly improved by matching the measuring light wavelength to the thickness between layers and by collecting high-order diffraction signals,promising a solution for future OVL metrology equipment.
