The requirements on the precision of dimensional metrology are especially stringent in the area of semiconductor manufacturing. This holds in particular for the measurement and control of the linewidths of the smalles...The requirements on the precision of dimensional metrology are especially stringent in the area of semiconductor manufacturing. This holds in particular for the measurement and control of the linewidths of the smallest structures on masks and silicon wafers and their corresponding reference metrology. In this paper we will describe the physical models and the reference instrumentation which were developed for photomask linewidth metrology at the PTB. It will be shown, how the results of the different methods can be used for comparative analyses. Application of these methods will be demonstrated exemplarily on the basis of newly developed photomask linewidth standards.展开更多
Recently,Coordinate Measuring Machines(CMMs)are widely used to measure roundness errors.Roundness is calculated from a large number of points collected from the profiles of the parts.According to the Guide to the Expr...Recently,Coordinate Measuring Machines(CMMs)are widely used to measure roundness errors.Roundness is calculated from a large number of points collected from the profiles of the parts.According to the Guide to the Expression of Uncertainty in Measurement(GUM),all measurement results must have a stated uncertainty associated the them.However,no CMMs give the uncertainty value of the roundness,because no suitable measurement uncertainty calculation procedure exists.In the case of roundness measurement in coordinate metrology,this paper suggests the algorithms for the calculation of the measurement uncertainty of the roundness deviation based on the two mainly used association criteria,LSC and MZC.The calculation of the sensitivity coefficients for the uncertainty calculation can be done by automatic differentiation,in order to avoid introducing additional errors by the traditional difference quotient approximations.The proposed methods are exact and need input data only as the measured coordinates of the data points and their associated uncertainties.展开更多
The PTB Josephson Arbitrary Waveform Synthesizer (JAWS) enables the generation of arbitrary waveforms up to voltages of 70 mVRMS (199 mVPP) using two Josephson arrays in series containing 4000 Josephson junctions each...The PTB Josephson Arbitrary Waveform Synthesizer (JAWS) enables the generation of arbitrary waveforms up to voltages of 70 mVRMS (199 mVPP) using two Josephson arrays in series containing 4000 Josephson junctions each. The SNS-like double-stacked junctions are based on NbxSi1-x as barrier material. While the JAWS system is typically operated using a Dewar with liquid helium, the operation in a closed-cycle pulse-tube cryocooler at temperatures around 4.2 K range was here investigated and successfully demonstrated. For this purpose a special designed cryoprobe was used to provide high quality pulses to the Josephson arrays.展开更多
Quantitative characterization of the mechanical properties of materials in micro-/nano-scale using depth-sensing indentation technique demands high performance of nanoindentation instruments in use. In this paper, the...Quantitative characterization of the mechanical properties of materials in micro-/nano-scale using depth-sensing indentation technique demands high performance of nanoindentation instruments in use. In this paper, the efforts to calibrate the capacitive force transducer of a commercial nanoindentation instrument are presented, where the quasi-static characteristic of the force transducer has been calibrated by a precise compensation balance with a resolution of ~1 nN. To investigate the dynamic response of the transducer, an electrostatic MEMS (Micro-Electro-Mechanical System) based on nano-force transfer standard with nano-Newton (10-9 Newton) resolution and a bandwidth up to 6 kHz have been employed. Preliminary experimental results indicate that 1) the force transducer under calibration has a probing force uncertainty less than 300 nN (1σ) in the calibration range of 1 mN;2) the transient duration at contact points amounts to 10 seconds;3) the overshoot of engagement is pre-load dependent.展开更多
At Physikalisch-Technische Bundesanstalt (PTB), superconducting 10 V circuits for the programmable Josephson voltage standard (PJVS) are routinely manufactured on the basis of NbxSi1-x barrier junctions. This paper de...At Physikalisch-Technische Bundesanstalt (PTB), superconducting 10 V circuits for the programmable Josephson voltage standard (PJVS) are routinely manufactured on the basis of NbxSi1-x barrier junctions. This paper describes in detail the basic design principles for an operating frequency of 70 GHz. It starts with single junctions, discusses their insertion into microstriplines and closes with the whole microwave circuit containing 69,632 NbxSi1-x barrier junctions arranged over 128 microstriplines connected in parallel. The microwave attenuation of this junction type is a key parameter for the 10 V design and we report its experimental determination. Special attention has been devoted to subarrays with just a few Josephson junctions in one of the outermost striplines. The arrangement of these subarrays determines the optimum performance of the complete 10 V series array. The high performance of programmable 10 V circuits fabricated at PTB is characterized by measured operating margins in all subarrays of more than 1 mA centered at the same dc bias current. The observed modulation of the current margins, when changing the frequency around 70 GHz, is explained by microwave reflections caused by the rf waveguide inside the cryoprobe. We determine the current margins in dependence of the output power of a microwave synthesizer and show that 60 mW is sufficient to achieve current margins larger than 1 mA.展开更多
Silica gel (SG) was synthesized via acidification of sodium silicate solution then doped with Fˉ or Zr(IV) in molar ratios of F/Si 3/100, and Zr/Si 0.75/100 and 3.75/100 and sintered at 500°C, 800°C and 100...Silica gel (SG) was synthesized via acidification of sodium silicate solution then doped with Fˉ or Zr(IV) in molar ratios of F/Si 3/100, and Zr/Si 0.75/100 and 3.75/100 and sintered at 500°C, 800°C and 1000°C. The samples were investigated by X-ray diffractometry, infrared absorption and Raman spectra, surface area measurement, and inductively coupled plasma-optical emission spectrometry-monitored silica hydrolysis. All samples are mesoporous with BET surface areas 181.5 - 523.9 m2·gˉ1. The surface area of the silica samples decreases as the sintering temperature increases. The hydrolysis process of silica decreases as the sintering temperature increases and as the surface area decreases. The pH and the type of buffer solution affect the hydrolysis of silica samples due to a SN2 reaction mechanism favored in basic media using ammonia buffer. Zr(IV) increases the stability of silica samples against the hydrolysis as confirmed by the structural investigation, surface area and silica hydrolysis. Fˉ observably decreases the silica hydrolysis process when presenting on the surface of SG.展开更多
For improving the performance of optical frequency dissemination and the resolution of its out-of-loop(OOL)characterization,we investigate a compact free-space interferometer design in which a monolithic assembly form...For improving the performance of optical frequency dissemination and the resolution of its out-of-loop(OOL)characterization,we investigate a compact free-space interferometer design in which a monolithic assembly forms the reference arm.Two interferometer designs are realized,and their environmental sensitivity is analyzed based on the properties of the materials involved.We elucidate that in these designs the temperature sensitivities of the out-of-loop signal paths are greater than for the reference arm.As the estimated temperature-variation-induced frequency transfer errors are observed to be the relevant limitation,the out-of-loop characterization signal can be regarded as a trustworthy upper limit of the frequency transfer error to a remote place.We demonstrate a fractional frequency transfer uncertainty and OOL characterization resolution of≤2.7×10^(-21)over many measurement runs.With a value of(0.23±1.07)×10^(-22)the weighted mean offset is significantly below the best reported results so far.展开更多
Pseudospin is an angular momentum degree of freedom introduced in analogy to the real electron spin in the effective massless Dirac-like equation used to describe wave evolution at conical intersections such as the Di...Pseudospin is an angular momentum degree of freedom introduced in analogy to the real electron spin in the effective massless Dirac-like equation used to describe wave evolution at conical intersections such as the Dirac cones of graphene.Here,we study a photonic implementation of a chiral borophene allotrope hosting a pseudospin-2 conical intersection in its energy-momentum spectrum.The presence of this fivefold spectral degeneracy gives rise to quasiparticles with pseudospin up to±2.We report on conical diffraction and pseudospin-orbit interaction of light in photonic chiral borophene,which,as a result of topological charge conversion,leads to the generation of highly charged optical phase vortices.展开更多
Near-field holography(NFH), with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduce...Near-field holography(NFH), with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduced by the integration of antireflective coatings(ARCs) simplifies the NFH process relative to that of setups using refractive index liquids. Based on the proposed NFH with ARCs, gold-coated laminar gratings were fabricated using NFH and subsequent ion beam etching. The efficiency angular spectrum shows that the stray light of the gratings is reduced one level of magnitude by the suppression of interface reflections during NFH.展开更多
The rapid development of display technologies has raised interest in arrays of self-emitting,individually controlled light sources atthe microscale.Gallium nitride(GaN)micro-light-emitting diode(LED)technology meets t...The rapid development of display technologies has raised interest in arrays of self-emitting,individually controlled light sources atthe microscale.Gallium nitride(GaN)micro-light-emitting diode(LED)technology meets this demand.However,the current technology is not suitable for the fabrication of arrays of submicron light sources that can be controlled individually.Our approach is based on nanoLED arrays that can directly address each array element and a self-pitch with dimensions below the wavelength of light.The design and fabrication processes are explained in detail and possess two geometries:a 6×6 array with 400 nm LEDs and a 2×32 line array with 200 nm LEDs.These nanoLEDs are developed as core elements of a novel on-chip super-resolution microscope.GaN technology,based on its physical properties,is an ideal platform for such nanoLEDs.展开更多
The correlation of single-particle imaging and absorption spectroscopy made the development of sizing curves possible and enabled rapid size determination of semiconductor nanocrystals based solely on optical properti...The correlation of single-particle imaging and absorption spectroscopy made the development of sizing curves possible and enabled rapid size determination of semiconductor nanocrystals based solely on optical properties.The increasing demand and production of such materials has resulted in a question of comparability between existing models and adequate volume-weighted size-determining measurement techniques.Small-angle X-ray scattering(SAXS)is a well-established method for obtaining nanostructural information from particle systems while operating sample quantities up to a commercial scale with a large amount of statistically based data.This work utilizes laboratory SAXS to characterize cadmium selenide nanocrystals with band edge energies between 1.97 and 3.08 eV.The evaluation of the scattering patterns is based on an indirect Fourier transformation(IFT),while dimensional parameters are derived from the model-free pair distance distribution functions(Dmode and Dg),as well as the modeled volume(Dv)and number(Dn)-weighted size-density distributions.We find that comparable data from D̅n agree well with existing X-ray diffraction(XRD)and with transmission electron microscopy(TEM)results described in literature;this qualifies SAXS as an equivalent integral characterization method.Although based on an estimate,the radius of gyration yields equivalent accurate results.Additionally,corresponding volume-weighted data are shown that can be useful when transferring information to other techniques.Dmode parametrization represents the largest estimated size of the sample and implies that particles interact and deviate from the spherical morphology,whereas Dv demonstrates results not considering such effects.A full set of the parameters discussed quantifies the quality of a sample.展开更多
Smaller and more complex three-dimensional periodic nanostructures are part of the next generation of integrated electronic circuits.Additionally,decreasing the dimensions of nanostructures increases the effect of lin...Smaller and more complex three-dimensional periodic nanostructures are part of the next generation of integrated electronic circuits.Additionally,decreasing the dimensions of nanostructures increases the effect of line-edge roughness on the performance of the nanostructures.Efficient methods for characterizing three-dimensional nanostructures are required for process control.Here,extreme-ultraviolet(EUV)scatterometry is exploited for the analysis of line-edge roughness from periodic nanostructures.In line with previous observations,differences are observed between line edge and line width roughness.The angular distribution of the diffuse scattering is an interplay of the line shape,the height of the structure,the roughness along the line,and the correlation between the lines.Unfortunately,existing theoretical methods for characterizing nanostructures using scatterometry do not cover all these aspects.Examples are shown here and the demands for future development of theoretical approaches for computing the angular distribution of the scattered X-rays are discussed.展开更多
Accurate metrology of extreme ultraviolet (EUV) photomask is a crucial task. In this paper, two different methods for reference EUV photomask metrology are compared. One is the critical dimension atomic force microsco...Accurate metrology of extreme ultraviolet (EUV) photomask is a crucial task. In this paper, two different methods for reference EUV photomask metrology are compared. One is the critical dimension atomic force microscopy (CD-AFM). In the measurements, the contribution of its AFM tip geometry is usually the dominant error source, as measured AFM images are the dilated results of measured structures by the AFM tip geometry. To solve this problem, a bottom-up approach has been applied in calibrating the (effective) AFM tip geometry where the result is traceably calibrated to the lattice constant of silicon crystals. The other is transmission electron microscopy (TEM). For achieving measurement traceability, structure features are measured in pairs in TEM images;thus the distance between the structure pair calibrated by a metrological AFM in prior can be applied to determine the magnification of the TEM image. In this study, selected photomask structures are calibrated by the CD-AFM, and then sample prepared and measured by high-resolution TEM nearly at the same location. The results are then compared. Of six feature groups compared, the results agree well within the measurement uncertainty, indicating excellent performance of the developed methodology. This research supports the development of a photomask standard, which is applied as a “reference ruler” with improved low measurement uncertainty in photomask fabs.展开更多
文摘The requirements on the precision of dimensional metrology are especially stringent in the area of semiconductor manufacturing. This holds in particular for the measurement and control of the linewidths of the smallest structures on masks and silicon wafers and their corresponding reference metrology. In this paper we will describe the physical models and the reference instrumentation which were developed for photomask linewidth metrology at the PTB. It will be shown, how the results of the different methods can be used for comparative analyses. Application of these methods will be demonstrated exemplarily on the basis of newly developed photomask linewidth standards.
基金supported by the National Natural Science Foundation of China(No.50705002,50627501)
文摘Recently,Coordinate Measuring Machines(CMMs)are widely used to measure roundness errors.Roundness is calculated from a large number of points collected from the profiles of the parts.According to the Guide to the Expression of Uncertainty in Measurement(GUM),all measurement results must have a stated uncertainty associated the them.However,no CMMs give the uncertainty value of the roundness,because no suitable measurement uncertainty calculation procedure exists.In the case of roundness measurement in coordinate metrology,this paper suggests the algorithms for the calculation of the measurement uncertainty of the roundness deviation based on the two mainly used association criteria,LSC and MZC.The calculation of the sensitivity coefficients for the uncertainty calculation can be done by automatic differentiation,in order to avoid introducing additional errors by the traditional difference quotient approximations.The proposed methods are exact and need input data only as the measured coordinates of the data points and their associated uncertainties.
文摘The PTB Josephson Arbitrary Waveform Synthesizer (JAWS) enables the generation of arbitrary waveforms up to voltages of 70 mVRMS (199 mVPP) using two Josephson arrays in series containing 4000 Josephson junctions each. The SNS-like double-stacked junctions are based on NbxSi1-x as barrier material. While the JAWS system is typically operated using a Dewar with liquid helium, the operation in a closed-cycle pulse-tube cryocooler at temperatures around 4.2 K range was here investigated and successfully demonstrated. For this purpose a special designed cryoprobe was used to provide high quality pulses to the Josephson arrays.
文摘Quantitative characterization of the mechanical properties of materials in micro-/nano-scale using depth-sensing indentation technique demands high performance of nanoindentation instruments in use. In this paper, the efforts to calibrate the capacitive force transducer of a commercial nanoindentation instrument are presented, where the quasi-static characteristic of the force transducer has been calibrated by a precise compensation balance with a resolution of ~1 nN. To investigate the dynamic response of the transducer, an electrostatic MEMS (Micro-Electro-Mechanical System) based on nano-force transfer standard with nano-Newton (10-9 Newton) resolution and a bandwidth up to 6 kHz have been employed. Preliminary experimental results indicate that 1) the force transducer under calibration has a probing force uncertainty less than 300 nN (1σ) in the calibration range of 1 mN;2) the transient duration at contact points amounts to 10 seconds;3) the overshoot of engagement is pre-load dependent.
文摘At Physikalisch-Technische Bundesanstalt (PTB), superconducting 10 V circuits for the programmable Josephson voltage standard (PJVS) are routinely manufactured on the basis of NbxSi1-x barrier junctions. This paper describes in detail the basic design principles for an operating frequency of 70 GHz. It starts with single junctions, discusses their insertion into microstriplines and closes with the whole microwave circuit containing 69,632 NbxSi1-x barrier junctions arranged over 128 microstriplines connected in parallel. The microwave attenuation of this junction type is a key parameter for the 10 V design and we report its experimental determination. Special attention has been devoted to subarrays with just a few Josephson junctions in one of the outermost striplines. The arrangement of these subarrays determines the optimum performance of the complete 10 V series array. The high performance of programmable 10 V circuits fabricated at PTB is characterized by measured operating margins in all subarrays of more than 1 mA centered at the same dc bias current. The observed modulation of the current margins, when changing the frequency around 70 GHz, is explained by microwave reflections caused by the rf waveguide inside the cryoprobe. We determine the current margins in dependence of the output power of a microwave synthesizer and show that 60 mW is sufficient to achieve current margins larger than 1 mA.
基金partly funded by the Alexander von Humboldt foundation,Germany,in the frame of a fellowship award.
文摘Silica gel (SG) was synthesized via acidification of sodium silicate solution then doped with Fˉ or Zr(IV) in molar ratios of F/Si 3/100, and Zr/Si 0.75/100 and 3.75/100 and sintered at 500°C, 800°C and 1000°C. The samples were investigated by X-ray diffractometry, infrared absorption and Raman spectra, surface area measurement, and inductively coupled plasma-optical emission spectrometry-monitored silica hydrolysis. All samples are mesoporous with BET surface areas 181.5 - 523.9 m2·gˉ1. The surface area of the silica samples decreases as the sintering temperature increases. The hydrolysis process of silica decreases as the sintering temperature increases and as the surface area decreases. The pH and the type of buffer solution affect the hydrolysis of silica samples due to a SN2 reaction mechanism favored in basic media using ammonia buffer. Zr(IV) increases the stability of silica samples against the hydrolysis as confirmed by the structural investigation, surface area and silica hydrolysis. Fˉ observably decreases the silica hydrolysis process when presenting on the surface of SG.
基金Deutsche Forschungsgemeinschaft(CRC 1464Terra-Q(Project-ID 434617780)EXC-2123 Quantum Frontiers(Project-ID 390837967))European Metrology Programme for Innovation and Research(18SIB06 TiFOON)。
文摘For improving the performance of optical frequency dissemination and the resolution of its out-of-loop(OOL)characterization,we investigate a compact free-space interferometer design in which a monolithic assembly forms the reference arm.Two interferometer designs are realized,and their environmental sensitivity is analyzed based on the properties of the materials involved.We elucidate that in these designs the temperature sensitivities of the out-of-loop signal paths are greater than for the reference arm.As the estimated temperature-variation-induced frequency transfer errors are observed to be the relevant limitation,the out-of-loop characterization signal can be regarded as a trustworthy upper limit of the frequency transfer error to a remote place.We demonstrate a fractional frequency transfer uncertainty and OOL characterization resolution of≤2.7×10^(-21)over many measurement runs.With a value of(0.23±1.07)×10^(-22)the weighted mean offset is significantly below the best reported results so far.
文摘Pseudospin is an angular momentum degree of freedom introduced in analogy to the real electron spin in the effective massless Dirac-like equation used to describe wave evolution at conical intersections such as the Dirac cones of graphene.Here,we study a photonic implementation of a chiral borophene allotrope hosting a pseudospin-2 conical intersection in its energy-momentum spectrum.The presence of this fivefold spectral degeneracy gives rise to quasiparticles with pseudospin up to±2.We report on conical diffraction and pseudospin-orbit interaction of light in photonic chiral borophene,which,as a result of topological charge conversion,leads to the generation of highly charged optical phase vortices.
基金supported by the Sino-German Center for Research Promotion (No.GZ 983)the German Science Foundation DFG (No.IRTG 2101)+1 种基金the Joint Fund of the National Natural Science Foundation of Chinathe China Academy of Engineering Physics (No.U1230104)
文摘Near-field holography(NFH), with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduced by the integration of antireflective coatings(ARCs) simplifies the NFH process relative to that of setups using refractive index liquids. Based on the proposed NFH with ARCs, gold-coated laminar gratings were fabricated using NFH and subsequent ion beam etching. The efficiency angular spectrum shows that the stray light of the gratings is reduced one level of magnitude by the suppression of interface reflections during NFH.
基金This work was funded by the European Union’s Horizon 2020 research and innovation program within the project of ChipScope under grant agreement no.737089by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy-EXC-2123 QuantumFrontiers-390837967。
文摘The rapid development of display technologies has raised interest in arrays of self-emitting,individually controlled light sources atthe microscale.Gallium nitride(GaN)micro-light-emitting diode(LED)technology meets this demand.However,the current technology is not suitable for the fabrication of arrays of submicron light sources that can be controlled individually.Our approach is based on nanoLED arrays that can directly address each array element and a self-pitch with dimensions below the wavelength of light.The design and fabrication processes are explained in detail and possess two geometries:a 6×6 array with 400 nm LEDs and a 2×32 line array with 200 nm LEDs.These nanoLEDs are developed as core elements of a novel on-chip super-resolution microscope.GaN technology,based on its physical properties,is an ideal platform for such nanoLEDs.
基金The authors thank the Laboratory for Nano and Quantum Engineering(LNQE),Leibniz University Hannover,for the access to the TEM instrument and Dr.Brian Pauw from the Bundesanstalt für Materialforschung und-prüfung(BAM)in Berlin for the scientific discussion about SAXS and the provision of the Ag-reference.We also acknowledge the work of David Niedbalka and Marcel Pastuschek who contributed to this research during their time as students.This research was partially funded by Niedersächsisches Ministerium für Wissenschaft und Kultur through the“Quantumand Nano-Metrology(QUANOMET)”initiative(ZN3245)within the scope of the NP-1 project.Furthermore,we acknowledge financial travel support by the DFG Research Training Group GrK1952“Metrology for Complex Nanosystems(NanoMet)”.
文摘The correlation of single-particle imaging and absorption spectroscopy made the development of sizing curves possible and enabled rapid size determination of semiconductor nanocrystals based solely on optical properties.The increasing demand and production of such materials has resulted in a question of comparability between existing models and adequate volume-weighted size-determining measurement techniques.Small-angle X-ray scattering(SAXS)is a well-established method for obtaining nanostructural information from particle systems while operating sample quantities up to a commercial scale with a large amount of statistically based data.This work utilizes laboratory SAXS to characterize cadmium selenide nanocrystals with band edge energies between 1.97 and 3.08 eV.The evaluation of the scattering patterns is based on an indirect Fourier transformation(IFT),while dimensional parameters are derived from the model-free pair distance distribution functions(Dmode and Dg),as well as the modeled volume(Dv)and number(Dn)-weighted size-density distributions.We find that comparable data from D̅n agree well with existing X-ray diffraction(XRD)and with transmission electron microscopy(TEM)results described in literature;this qualifies SAXS as an equivalent integral characterization method.Although based on an estimate,the radius of gyration yields equivalent accurate results.Additionally,corresponding volume-weighted data are shown that can be useful when transferring information to other techniques.Dmode parametrization represents the largest estimated size of the sample and implies that particles interact and deviate from the spherical morphology,whereas Dv demonstrates results not considering such effects.A full set of the parameters discussed quantifies the quality of a sample.
基金funding from the Electronic Component Systems for European Leadership Joint Undertaking under grant agreement No 826589|MADEin4This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and The Netherlands,France,Belgium,Germany,Czech Republic,Austria,Hungary,and IsraelOpen Access funding enabled and organized by Projekt DEAL.
文摘Smaller and more complex three-dimensional periodic nanostructures are part of the next generation of integrated electronic circuits.Additionally,decreasing the dimensions of nanostructures increases the effect of line-edge roughness on the performance of the nanostructures.Efficient methods for characterizing three-dimensional nanostructures are required for process control.Here,extreme-ultraviolet(EUV)scatterometry is exploited for the analysis of line-edge roughness from periodic nanostructures.In line with previous observations,differences are observed between line edge and line width roughness.The angular distribution of the diffuse scattering is an interplay of the line shape,the height of the structure,the roughness along the line,and the correlation between the lines.Unfortunately,existing theoretical methods for characterizing nanostructures using scatterometry do not cover all these aspects.Examples are shown here and the demands for future development of theoretical approaches for computing the angular distribution of the scattered X-rays are discussed.
基金Open Access funding enabled and organized by Projekt DEAL.
文摘Accurate metrology of extreme ultraviolet (EUV) photomask is a crucial task. In this paper, two different methods for reference EUV photomask metrology are compared. One is the critical dimension atomic force microscopy (CD-AFM). In the measurements, the contribution of its AFM tip geometry is usually the dominant error source, as measured AFM images are the dilated results of measured structures by the AFM tip geometry. To solve this problem, a bottom-up approach has been applied in calibrating the (effective) AFM tip geometry where the result is traceably calibrated to the lattice constant of silicon crystals. The other is transmission electron microscopy (TEM). For achieving measurement traceability, structure features are measured in pairs in TEM images;thus the distance between the structure pair calibrated by a metrological AFM in prior can be applied to determine the magnification of the TEM image. In this study, selected photomask structures are calibrated by the CD-AFM, and then sample prepared and measured by high-resolution TEM nearly at the same location. The results are then compared. Of six feature groups compared, the results agree well within the measurement uncertainty, indicating excellent performance of the developed methodology. This research supports the development of a photomask standard, which is applied as a “reference ruler” with improved low measurement uncertainty in photomask fabs.