We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1...We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1</sup>, are reported. These levels classify altogether 67 lines, not listed in spectral tables. The new levels were found due to the observation of the depopulation of the lower levels of the excited transitions. We found a remarkable variation of the observed widths of single hyperfine structure components dependent on the energy of the upper excited levels. Some levels having energies higher than 43,000 cm<sup>-1</sup> appear to have a very high ionization probability.展开更多
The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibra...The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibrate the corresponding instruments.We develop a new reference material with nominal CDs of 160 nm,80 nm,and 40 nm.The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology(NIM)in China.Also,we propose a new characterization method for the precise measurement of CD values.After filtering and leveling the intensity profiles,the line features are characterized by the combination model of the Gaussian and Lorentz functions.The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm.Then the width of the two edges at the half intensity position is regarded as the standard CD value.Finally,the measurement results are evaluated in terms of the sample,instrument,algorithm,and repeatability.The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.展开更多
The influences of different buffer gas, neon and helium, on 199^Hg^＋ clock transition are compared in trapped 199^Hg^＋ linear trap. By the technique of time domain＇s Ramsey separated oscillatory fields, the buffer...The influences of different buffer gas, neon and helium, on 199^Hg^＋ clock transition are compared in trapped 199^Hg^＋ linear trap. By the technique of time domain＇s Ramsey separated oscillatory fields, the buffer gas pressure frequency shifts of 199^Hg^＋ clock transition are measured to be （df/dPNe）（1/f） = 1.8 × 10^-8 Torr^-1 for neon and （df/dPHe） （1/f） = 9.1 × 10^-8 Torr^-1 for helium. Meanwhile, the line-width of 199^Hg^＋ clock transition spectrum with the buffer gas neon is narrower than that with helium at the same pressure. These experimental results show that neon is a more suitable buffer gas than helium in 199^Hg^＋ ions microwave frequency standards because of the 199^Hg^＋ clock transition is less sensitive to neon variations and the better cooling effect of neon. The optimum operating pressure for neon is found to be about 1.0 × 10^-5 Torr in our linear ion trap system.展开更多
We propose a technique to precisely measure the line width of the photoassociation spectra of the excited cesium molecule by using a frequency shifter to generate two laser beams with a precise frequency difference. A...We propose a technique to precisely measure the line width of the photoassociation spectra of the excited cesium molecule by using a frequency shifter to generate two laser beams with a precise frequency difference. A series of photoassociation （PA） spectra are recorded with two laser beam induced molecular lines, whose peak separation serves as an accurate frequency ruler to measure the line width of the PA spectra. The full width half maximum line width was studied as a function of PA laser intensity. The extrapolated value at zero laser intensity is （34.8± 0.22） MHz. By analyzing other broadening mechanisms, a value of （32.02 ± 0.70） MHz was deduced. It is shown that this scheme is inexpensive, simple, robust, and is promising for applications in a variety of other atomic species.展开更多
A quasicrystal has a structure intermediate between crystals and compound glasses. The disorder in glass makes its diffraction diffuse, so it is surprising that quasicrystals diffract more sharply than crystals. The g...A quasicrystal has a structure intermediate between crystals and compound glasses. The disorder in glass makes its diffraction diffuse, so it is surprising that quasicrystals diffract more sharply than crystals. The greater sharpness is computed to be due to the hierarchic structure with unit cell alignment in 3-dimensional space. Electron microscope phase contrast images map the comparatively heavy Mn atoms in icosahedral Al<sub>6</sub>Mn, where the transition metal locates the centers of unit cells inside clusters and superclusters. Because the solid is aperiodic, each diffracted beam is a product of multiple interplanar spacings combined, and this contrasts with the unique relationship between spacing and incident angle in Bragg diffraction from crystals. Simulated quasi-structure factors add the relative phase shifts that are in geometric series from cell to cluster to superclusters of increasing order. The scattering becomes coherent in best fit, angular configuration between the aperiodic solid and a longitudinally periodic X-ray or electron probe. The quasi-structure factors express angular divergence in each diffracted beam from its corresponding Bragg condition, and the divergence provides a special metric, essential for atomic measurement in the geometric solids. The fit is reinforced at all levels from the unit cell to cluster to high order superclusters. The optics operates under a new quasi-Bragg law in a new geometric space. In this paper, we proceed to examine the effect of specimen size on line resolution in diffraction, first analytically and secondly in simulation. The line resolution follows a power law on the supercluster order, matching its atomic population.展开更多
Low-temperature fired ferrites or ceramics are usually processed by using low-melting materials(e.g.,glasses,oxides,and eutectics)as sintering aids to obtain compact and uniform microstructures.Herein,a dual-strategy ...Low-temperature fired ferrites or ceramics are usually processed by using low-melting materials(e.g.,glasses,oxides,and eutectics)as sintering aids to obtain compact and uniform microstructures.Herein,a dual-strategy of co-doping with V_(2)O_(5)and Sb_(2)O_(3)oxides and forming a eutectic liquid phase has been employed to reduce the melting point of LiZn ferrite ceramics in an effective way.The results indicate that miniscule amounts of V_(2)O_(5)and Sb_(2)O_(3)co-doping contribute in producing dense and uniform microstructures with enhanced magnetic performance by low-temperature firing.The phase structural and microstructural evolutions have been studied in detail.Thereafter their correlations with magnetic properties have been revealed.Enhanced magnetic performance(B_(s)=475.4 mT,M_(s)=82.51 emu/g,B_(r)/B_(s)=0.85,H_(c)=2.2 Oe,ΔH=153.8 Oe)of the LiZn-based ferrite ceramics is achieved by optimized composition and microstructure,which shows great potential for microwave applications including phase shifters and radars.More importantly,such a co-doping strategy can be also extended to other material systems,like dielectric ceramics,hexagonal ferrites or piezoelectric ceramics.展开更多
C NMR spin-lattice relaxation times (T1), line widths, nuclear Overhauser effects (NOE) at room temperature have been measured for radiated ets 1,4-polybutadiene.With the increase of radiation dose T1 is almost invari...C NMR spin-lattice relaxation times (T1), line widths, nuclear Overhauser effects (NOE) at room temperature have been measured for radiated ets 1,4-polybutadiene.With the increase of radiation dose T1 is almost invariant, but line width of the methylene (-CH2-) carbon increases remarkably, and its NOE factor decreases sharply. This implies that the long-range segmental motion is hindered, and saturated tertiary carbon (-C H- ) is formed during crosslinking of ets 1,4-polybutadiene.展开更多
Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. T...Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. The sunken defects proposed in this paper is a w idth abnormity defect on the FPC trace,w hich w ould cause the latent open circuit defect and affect the electrical function of circuit. The problem of flexible deformation and w idth difference make the FPC trace detection harder. Therefore,this paper proposed a detection scheme combined w ith linear masks and circle distribution characteristic. Firstly,this scheme preprocessed the acquired FPC image,divided the trace into several sub-regions and obtained the line w idth values of each trace transverse section. Then the line w idth sequences w ere searched w ith the linear difference template of gray scale. Thus,the sunken defects alternative positions w ere located. Lastly,the circle distribution characteristic is defined to identify the real defect areas from the alternative regions acquired from the previous step. Thus,the detection of sunken defects on the FPC trace w as accomplished.The algorithm w as tested in the self-built image database,w hich show s the better detection performance than the other typical algorithms.展开更多
The present study was conducted to identify quantitative trait loci （QTLs） for leaf size traits in IR64 introgression lines （INLs）. For this purpose, selected F2 populations derived from crosses between recurrent ...The present study was conducted to identify quantitative trait loci （QTLs） for leaf size traits in IR64 introgression lines （INLs）. For this purpose, selected F2 populations derived from crosses between recurrent parent IR64 and its derived INLs, unique for leaf length and leaf width, were used to confirm QTLs. A total of eight QTLs, mapped on three chromosomes, were identified for the four leaf size traits in six F2 populations. A QTL for leaf length, qLLnpt-1, in HKL69 was identified around simple sequence repeat （SSR） marker RM3709 on chromosome 1. Two QTLs for flag leaf length, qFLLnpt-2 and qFLLnpt-4, in HFG39 were indentified on chromosomes 2 and 4, respectively. For flag leaf width, a QTL, qFLWnpt-4, in HFG39 was identified around RM17483 on chromosome 4. While another QTL for flag leaf width, qFLWnpt-1, in HFG27 was identified around RM3252 on chromosome 1. A QTL for leaf width, qLWnpt-2, in HKL75 was identified around RM7451 on chromosome 2. For leaf width, two QTLs, qLWnpt-4a, qLWnpt-4b, in HKL48 and HKL99 were identified around RM7208 and RM6909, respectively on chromosome 4. Results from this study suggest the possibilities to use marker-assisted selection and pyramiding these QTLs to improve rice water productivity.展开更多
Line width(i.e.,critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control the CD in manufacturing,a reasonable CD measurement algorithm is required.We develop an automatic and accurate ...Line width(i.e.,critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control the CD in manufacturing,a reasonable CD measurement algorithm is required.We develop an automatic and accurate method based on a two-dimensional discrete Fourier transform for measuring the lattice spacings from high-resolution transmission electron microscopy images.Through the two-dimensional inverse discrete Fourier transform of the central spot and a pair of symmetrical diffraction spots,an image containing only a set of lattice spacings is obtained.Then,the pixel span of the lattice spacing is calculated through the centre of gravity method.Finally,we estimate the standard CD value according to the half-intensity method.The silicon crystal lattice constant guarantees the accuracy and traceability of the CD value.Through experiments,we demonstrate the efficiency of the proposed method,which can be conveniently applied to accurately measure CDs in practical applications.展开更多
Environmentally persistent free radicals(EPFRs)are a new class of pollutants that are long-lived in fine particles(PM_(2.5)),i.e.,their 1/e lifetime ranges from days to months(or even infinite).They are capable of pro...Environmentally persistent free radicals(EPFRs)are a new class of pollutants that are long-lived in fine particles(PM_(2.5)),i.e.,their 1/e lifetime ranges from days to months(or even infinite).They are capable of producing harmful reactive oxygen species such as hydroxyl radicals.The redox cycling of EPFRs is considered as an important pathway for PM_(2.5) to induce oxidative stress inside the humans,causing adverse health effects such as respiratory and cardiovascular diseases.Conse-quently,research regarding their toxicity,formation and environmental occurrences in PM_(2.5) has attracted increasing atten-tions globally during the past two decades.However,literature data in this field remain quite limited and discrete.Hence,an extensive review is urgently needed to summarize the current understanding of this topic.In this work,we systematically reviewed the analytical methods and environmental occurrences,e.g.,types,concentrations,and decay behaviors,as well as possible sources of EPFRs in PM_(2.5).The types of pretreatment methods,g-values of common EPFRs and categories of decay processes were discussed in detail.Moreover,great efforts were made to revisit the original data of the published works of EPFRs in airborne particulate matter and provided additional useful information for comparison where possible,e.g.,their mean and standard deviation of g-values,line widths(ΔHp-p),and concentrations.Finally,possible research opportunities were highlighted to further advance our knowledge of this emerging issue.展开更多
Copper chemical mechanical polishing （CMP） is influenced by geometric characteristics such as line width and pattern density, as well as by the more obvious parameters such as slurry chemistry, pad type, polishing p...Copper chemical mechanical polishing （CMP） is influenced by geometric characteristics such as line width and pattern density, as well as by the more obvious parameters such as slurry chemistry, pad type, polishing pressure and rotational speed. Variations in the copper thickness across each die and across the wafer can impact the circuit performance and reduce the yield. In this paper, we propose a modeling method to simulate the polishing behavior as a function of layout pattern factors. Under the same process conditions, the pattern density, the line width and the line spacing have a strong influence on copper dishing, dielectric erosion and topography. The test results showed： the wider the copper line or the spacing, the higher the copper dishing; the higher the density, the higher the dielectric erosion; the dishing and erosion increase slowly as a function of increasing density and go into saturation when the density is more than 0.7.展开更多
文摘We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1</sup>, are reported. These levels classify altogether 67 lines, not listed in spectral tables. The new levels were found due to the observation of the depopulation of the lower levels of the excited transitions. We found a remarkable variation of the observed widths of single hyperfine structure components dependent on the energy of the upper excited levels. Some levels having energies higher than 43,000 cm<sup>-1</sup> appear to have a very high ionization probability.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFF0218403)the Basic Scientific Research Operating Fund of NIM(Grant No.AKYZD2007-1)。
文摘The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibrate the corresponding instruments.We develop a new reference material with nominal CDs of 160 nm,80 nm,and 40 nm.The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology(NIM)in China.Also,we propose a new characterization method for the precise measurement of CD values.After filtering and leveling the intensity profiles,the line features are characterized by the combination model of the Gaussian and Lorentz functions.The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm.Then the width of the two edges at the half intensity position is regarded as the standard CD value.Finally,the measurement results are evaluated in terms of the sample,instrument,algorithm,and repeatability.The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.
基金supported by the National Natural Science Foundation of China(Grant No.11074248)
文摘The influences of different buffer gas, neon and helium, on 199^Hg^＋ clock transition are compared in trapped 199^Hg^＋ linear trap. By the technique of time domain＇s Ramsey separated oscillatory fields, the buffer gas pressure frequency shifts of 199^Hg^＋ clock transition are measured to be （df/dPNe）（1/f） = 1.8 × 10^-8 Torr^-1 for neon and （df/dPHe） （1/f） = 9.1 × 10^-8 Torr^-1 for helium. Meanwhile, the line-width of 199^Hg^＋ clock transition spectrum with the buffer gas neon is narrower than that with helium at the same pressure. These experimental results show that neon is a more suitable buffer gas than helium in 199^Hg^＋ ions microwave frequency standards because of the 199^Hg^＋ clock transition is less sensitive to neon variations and the better cooling effect of neon. The optimum operating pressure for neon is found to be about 1.0 × 10^-5 Torr in our linear ion trap system.
基金Project supported by the National Basic Research Program of China (Grant No. 2012CB921603)the National High Technology Research and Development of China (Grant No. 2009AA01Z319)+3 种基金the National Natural Science Foundation of China (Grant Nos.61008012,10934004,60978018,60978001,60808009, and 11074154)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (Grant No. 60821004)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20101401120004)the National Natural Science Foundation of Shanxi Province,China (Grant No. 2009011059-2)
文摘We propose a technique to precisely measure the line width of the photoassociation spectra of the excited cesium molecule by using a frequency shifter to generate two laser beams with a precise frequency difference. A series of photoassociation （PA） spectra are recorded with two laser beam induced molecular lines, whose peak separation serves as an accurate frequency ruler to measure the line width of the PA spectra. The full width half maximum line width was studied as a function of PA laser intensity. The extrapolated value at zero laser intensity is （34.8± 0.22） MHz. By analyzing other broadening mechanisms, a value of （32.02 ± 0.70） MHz was deduced. It is shown that this scheme is inexpensive, simple, robust, and is promising for applications in a variety of other atomic species.
文摘A quasicrystal has a structure intermediate between crystals and compound glasses. The disorder in glass makes its diffraction diffuse, so it is surprising that quasicrystals diffract more sharply than crystals. The greater sharpness is computed to be due to the hierarchic structure with unit cell alignment in 3-dimensional space. Electron microscope phase contrast images map the comparatively heavy Mn atoms in icosahedral Al<sub>6</sub>Mn, where the transition metal locates the centers of unit cells inside clusters and superclusters. Because the solid is aperiodic, each diffracted beam is a product of multiple interplanar spacings combined, and this contrasts with the unique relationship between spacing and incident angle in Bragg diffraction from crystals. Simulated quasi-structure factors add the relative phase shifts that are in geometric series from cell to cluster to superclusters of increasing order. The scattering becomes coherent in best fit, angular configuration between the aperiodic solid and a longitudinally periodic X-ray or electron probe. The quasi-structure factors express angular divergence in each diffracted beam from its corresponding Bragg condition, and the divergence provides a special metric, essential for atomic measurement in the geometric solids. The fit is reinforced at all levels from the unit cell to cluster to high order superclusters. The optics operates under a new quasi-Bragg law in a new geometric space. In this paper, we proceed to examine the effect of specimen size on line resolution in diffraction, first analytically and secondly in simulation. The line resolution follows a power law on the supercluster order, matching its atomic population.
基金partly supported by“Double First-Rate of China”the National Natural Science Foundation of China(grant no.61734002)+1 种基金“the Fundamental Research Funds for Central Universities”(grant no.20826041D4125)the Sichuan Science and Technology Program(grant nos.2020JDR0016 and 2020ZDZX0008)
文摘Low-temperature fired ferrites or ceramics are usually processed by using low-melting materials(e.g.,glasses,oxides,and eutectics)as sintering aids to obtain compact and uniform microstructures.Herein,a dual-strategy of co-doping with V_(2)O_(5)and Sb_(2)O_(3)oxides and forming a eutectic liquid phase has been employed to reduce the melting point of LiZn ferrite ceramics in an effective way.The results indicate that miniscule amounts of V_(2)O_(5)and Sb_(2)O_(3)co-doping contribute in producing dense and uniform microstructures with enhanced magnetic performance by low-temperature firing.The phase structural and microstructural evolutions have been studied in detail.Thereafter their correlations with magnetic properties have been revealed.Enhanced magnetic performance(B_(s)=475.4 mT,M_(s)=82.51 emu/g,B_(r)/B_(s)=0.85,H_(c)=2.2 Oe,ΔH=153.8 Oe)of the LiZn-based ferrite ceramics is achieved by optimized composition and microstructure,which shows great potential for microwave applications including phase shifters and radars.More importantly,such a co-doping strategy can be also extended to other material systems,like dielectric ceramics,hexagonal ferrites or piezoelectric ceramics.
文摘C NMR spin-lattice relaxation times (T1), line widths, nuclear Overhauser effects (NOE) at room temperature have been measured for radiated ets 1,4-polybutadiene.With the increase of radiation dose T1 is almost invariant, but line width of the methylene (-CH2-) carbon increases remarkably, and its NOE factor decreases sharply. This implies that the long-range segmental motion is hindered, and saturated tertiary carbon (-C H- ) is formed during crosslinking of ets 1,4-polybutadiene.
文摘Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. The sunken defects proposed in this paper is a w idth abnormity defect on the FPC trace,w hich w ould cause the latent open circuit defect and affect the electrical function of circuit. The problem of flexible deformation and w idth difference make the FPC trace detection harder. Therefore,this paper proposed a detection scheme combined w ith linear masks and circle distribution characteristic. Firstly,this scheme preprocessed the acquired FPC image,divided the trace into several sub-regions and obtained the line w idth values of each trace transverse section. Then the line w idth sequences w ere searched w ith the linear difference template of gray scale. Thus,the sunken defects alternative positions w ere located. Lastly,the circle distribution characteristic is defined to identify the real defect areas from the alternative regions acquired from the previous step. Thus,the detection of sunken defects on the FPC trace w as accomplished.The algorithm w as tested in the self-built image database,w hich show s the better detection performance than the other typical algorithms.
文摘The present study was conducted to identify quantitative trait loci （QTLs） for leaf size traits in IR64 introgression lines （INLs）. For this purpose, selected F2 populations derived from crosses between recurrent parent IR64 and its derived INLs, unique for leaf length and leaf width, were used to confirm QTLs. A total of eight QTLs, mapped on three chromosomes, were identified for the four leaf size traits in six F2 populations. A QTL for leaf length, qLLnpt-1, in HKL69 was identified around simple sequence repeat （SSR） marker RM3709 on chromosome 1. Two QTLs for flag leaf length, qFLLnpt-2 and qFLLnpt-4, in HFG39 were indentified on chromosomes 2 and 4, respectively. For flag leaf width, a QTL, qFLWnpt-4, in HFG39 was identified around RM17483 on chromosome 4. While another QTL for flag leaf width, qFLWnpt-1, in HFG27 was identified around RM3252 on chromosome 1. A QTL for leaf width, qLWnpt-2, in HKL75 was identified around RM7451 on chromosome 2. For leaf width, two QTLs, qLWnpt-4a, qLWnpt-4b, in HKL48 and HKL99 were identified around RM7208 and RM6909, respectively on chromosome 4. Results from this study suggest the possibilities to use marker-assisted selection and pyramiding these QTLs to improve rice water productivity.
基金supported by Basic Scientific Research Operating Fund of NIM(Grant No.AKYZD2007-1).
文摘Line width(i.e.,critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control the CD in manufacturing,a reasonable CD measurement algorithm is required.We develop an automatic and accurate method based on a two-dimensional discrete Fourier transform for measuring the lattice spacings from high-resolution transmission electron microscopy images.Through the two-dimensional inverse discrete Fourier transform of the central spot and a pair of symmetrical diffraction spots,an image containing only a set of lattice spacings is obtained.Then,the pixel span of the lattice spacing is calculated through the centre of gravity method.Finally,we estimate the standard CD value according to the half-intensity method.The silicon crystal lattice constant guarantees the accuracy and traceability of the CD value.Through experiments,we demonstrate the efficiency of the proposed method,which can be conveniently applied to accurately measure CDs in practical applications.
基金the Ningbo Natural Science Foundation(Grant no.2018A610208)the National This work was supported by the Ningbo Natural Science Foundation(Grant no.2018A610208)the National Institute of Environmental Health Sciences(NIEHS)(Grant no.2P42ES013648)。
文摘Environmentally persistent free radicals(EPFRs)are a new class of pollutants that are long-lived in fine particles(PM_(2.5)),i.e.,their 1/e lifetime ranges from days to months(or even infinite).They are capable of producing harmful reactive oxygen species such as hydroxyl radicals.The redox cycling of EPFRs is considered as an important pathway for PM_(2.5) to induce oxidative stress inside the humans,causing adverse health effects such as respiratory and cardiovascular diseases.Conse-quently,research regarding their toxicity,formation and environmental occurrences in PM_(2.5) has attracted increasing atten-tions globally during the past two decades.However,literature data in this field remain quite limited and discrete.Hence,an extensive review is urgently needed to summarize the current understanding of this topic.In this work,we systematically reviewed the analytical methods and environmental occurrences,e.g.,types,concentrations,and decay behaviors,as well as possible sources of EPFRs in PM_(2.5).The types of pretreatment methods,g-values of common EPFRs and categories of decay processes were discussed in detail.Moreover,great efforts were made to revisit the original data of the published works of EPFRs in airborne particulate matter and provided additional useful information for comparison where possible,e.g.,their mean and standard deviation of g-values,line widths(ΔHp-p),and concentrations.Finally,possible research opportunities were highlighted to further advance our knowledge of this emerging issue.
文摘Copper chemical mechanical polishing （CMP） is influenced by geometric characteristics such as line width and pattern density, as well as by the more obvious parameters such as slurry chemistry, pad type, polishing pressure and rotational speed. Variations in the copper thickness across each die and across the wafer can impact the circuit performance and reduce the yield. In this paper, we propose a modeling method to simulate the polishing behavior as a function of layout pattern factors. Under the same process conditions, the pattern density, the line width and the line spacing have a strong influence on copper dishing, dielectric erosion and topography. The test results showed： the wider the copper line or the spacing, the higher the copper dishing; the higher the density, the higher the dielectric erosion; the dishing and erosion increase slowly as a function of increasing density and go into saturation when the density is more than 0.7.
