Direct-write atom lithography,one of the potential nanofabrication techniques,is restricted by some difficulties in producing optical masks for the deposition of complex structures.In order to make further progress,a ...Direct-write atom lithography,one of the potential nanofabrication techniques,is restricted by some difficulties in producing optical masks for the deposition of complex structures.In order to make further progress,a structured mirror array is developed to transversely collimate the chromium atomic beam in two dimensions.The best collimation is obtained when the laser red detunes by natural line-width of transition 7S3 → 7P40 of the chromium atom.The collimation ratio is 0.45 vertically(in x axis),and it is 0.55 horizontally(in y axis).The theoretical model is also simulated,and success of our structured mirror array is achieved.展开更多
Atom lithography is a unique method to fabricate self-traceable pitch standards and angle standards,but extending its structure area to millimeter-level for application is challenging.In this paper,on the one hand,we ...Atom lithography is a unique method to fabricate self-traceable pitch standards and angle standards,but extending its structure area to millimeter-level for application is challenging.In this paper,on the one hand,we put forward a new approach to fabricate a full-covered self-traceable Cr nanograting by inserting and scanning a Dove prism in the Gaussian beam direction of atom lithography.On the other hand,we extend the structure area along the standing-wave direction by splicing two-step atom deposition.Both nanostructures manufactured via scanning atom lithography and splicing atom lithography demonstrate good pitch accuracy,parallelism,continuity,and homogeneity,which opens a new way to fabricate centimeter-level full-covered self-traceable nanograting and lays the basis for the application of square ruler and optical encoders at the nanoscale.展开更多
Chromium atom photolithography gratings are a promising technology for the development of nanoscale length standard substances due to their high accuracy,uniformity,and consistency.However,the inherent difference betw...Chromium atom photolithography gratings are a promising technology for the development of nanoscale length standard substances due to their high accuracy,uniformity,and consistency.However,the inherent difference between the interaction of positive and negative frequency detuning standing wave field and the atoms can cause a difference in the adjacent peak-to-valley heights of the grating in positive and negative frequency detuning chromium atom lithography,which greatly reduces its accuracy.In this study,we performed a controlled variable growth simulation using the semi-classical theoretical model and Monte Carlo method with trajectory tracking and ballistic deposition methods to investigate the influence of key experimental parameters on the surface growth process of positive and negative frequency detuning atomic lithography gratings.We established a theoretical model based on simulation results and summarized empirical equations to guide the selection of experimental parameters.Our simulations achieved uniform positive and negative frequency detuning atomic lithography gratings with a period of 1/4 of the wavelength corresponding to the atomic transition frequency,and adjacent peak-to-valley heights differing by no more than 2 nm,providing an important theoretical reference for the controllable fabrication of these gratings.展开更多
The characteristics of neutral chromium atoms in the standing wave field are discussed. Based on a semi-classical model, the motion equation of neutral atoms in the laser standing wave field is analyzed, and the traje...The characteristics of neutral chromium atoms in the standing wave field are discussed. Based on a semi-classical model, the motion equation of neutral atoms in the laser standing wave field is analyzed, and the trajectories of the atoms are obtained by simulations with the different divergence angles of the atomic beam. The simulation results show that the full width at half maximum (FWHM) of the stripe is 2.75 nm and the contrast is 38.5 : 1 when the divergence angle equals 0 mrad, the FWHM is 24.1 nm and the contrast is 6.8:1 when the divergence angle equals 0.2 mrad and the FWHMs are 58.6 and 137.8 nm, and the contrasts are 3.3 : 1 and 1.6 : i when the divergence angles equal 0.5 and 1.0 mrad, respectively.展开更多
The use of the dipole force on atoms is a new technology that is used to build nanostructures. In this way, a high quality standard nano-grating can be obtained. Based on the semi-classical model, the motion equation ...The use of the dipole force on atoms is a new technology that is used to build nanostructures. In this way, a high quality standard nano-grating can be obtained. Based on the semi-classical model, the motion equation is investigated and the trajectories of atoms in double half Gaussian standing wave field are simulated. Compared with the Gaussian standing wave field, the double half Gaussian standing wave can well focus the Cr atoms. In order to obtain this kind of beam, a prism is designed and the experimental result shows that the beam is well generated.展开更多
Atom lithography with chromium can be utilized to fabricate a pitch standard, which is chrectly traceable to me wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrate...Atom lithography with chromium can be utilized to fabricate a pitch standard, which is chrectly traceable to me wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrates that the pitch standard is (212.8±0.1) nm with a peak-to-valley-height (PTVH) better than 20 nm. The measurement results show the high period accuracy of traceability with the standing laser wavelength (λ/2 = 212.78 nm). The Cr nano-grating covers a 1000μm×500 μm area, with a PTVH better than 10 nm. The feature width broadening of the Cr nanostructure has been experimentally observed along the direction of the standing waves. The PTVH along the Gaussian laser direction is similar to a Gaussian distribution. Highly uniform periodic nanostructures with a big area at the millimeter scale, and the surface growth uniformity of the Cr nano-grating, show its great potential in the application of a traceable pitch standard at trans-scales.展开更多
Working with a biased atomic force microscope(AFM)tip in the tapping mode under ambient atmosphere,attoliter(10^(-18) L)water droplet patterns have been generated on a patterned carbonaceous surface.This is essentiall...Working with a biased atomic force microscope(AFM)tip in the tapping mode under ambient atmosphere,attoliter(10^(-18) L)water droplet patterns have been generated on a patterned carbonaceous surface.This is essentially electrocondensation of water leading to charged droplets,as evidenced from electrostatic force microscopy measurements.The droplets are unusual in that they exhibit a highly corrugated surface and evaporate rather slowly,taking several tens of minutes.展开更多
基金Project supported by the Shanghai Nanoscience Foundation,China (Grant Nos. 0852nm07000 and 0952nm07000)the National Natural Science Foundation of China (Grant Nos. 10804084 and 91123022)+1 种基金the National Key Technology R & D Program,China (Grant No. 2006BAF06B08)the Specialized Research Fund for the Doctoral Program of Ministry of High Education of China (Grant No. 200802471008)
文摘Direct-write atom lithography,one of the potential nanofabrication techniques,is restricted by some difficulties in producing optical masks for the deposition of complex structures.In order to make further progress,a structured mirror array is developed to transversely collimate the chromium atomic beam in two dimensions.The best collimation is obtained when the laser red detunes by natural line-width of transition 7S3 → 7P40 of the chromium atom.The collimation ratio is 0.45 vertically(in x axis),and it is 0.55 horizontally(in y axis).The theoretical model is also simulated,and success of our structured mirror array is achieved.
基金supported by Significant Development Project of Shanghai Zhangjiang National Innovation Benchmarking Zone(Grant No.ZJ2021-ZD-008)National Natural Science Foundation of China(Grant No.62075165)+3 种基金Science and Technology Commission of Shanghai(Grant No.208014043)Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)the Fundamental Research Funds for the Central UniversitiesOpening Fund from Shanghai Key Laboratory of Online Detection and Control Technology of SIMT.
文摘Atom lithography is a unique method to fabricate self-traceable pitch standards and angle standards,but extending its structure area to millimeter-level for application is challenging.In this paper,on the one hand,we put forward a new approach to fabricate a full-covered self-traceable Cr nanograting by inserting and scanning a Dove prism in the Gaussian beam direction of atom lithography.On the other hand,we extend the structure area along the standing-wave direction by splicing two-step atom deposition.Both nanostructures manufactured via scanning atom lithography and splicing atom lithography demonstrate good pitch accuracy,parallelism,continuity,and homogeneity,which opens a new way to fabricate centimeter-level full-covered self-traceable nanograting and lays the basis for the application of square ruler and optical encoders at the nanoscale.
基金Project supported by the National Natural Science Foundation of China(Grant No.62075165)the National Key Research and Development Program of China(Grant Nos.2022YFF0607600 and 2022YFF0605502)+3 种基金the Special Development Funds for Major Projects of Shanghai Zhangjiang National Independent Innovation Demonstration Zone(Grant No.ZJ2021ZD008)the Shanghai Natural Science Foundation(Grant No.21ZR1483100)the Shanghai Academic/Technology Research Leader(Grant No.21XD1425000)the Opening Fund of Shanghai Key Laboratory of Online Detection and Control Technology(Grant No.ZX2020101)。
文摘Chromium atom photolithography gratings are a promising technology for the development of nanoscale length standard substances due to their high accuracy,uniformity,and consistency.However,the inherent difference between the interaction of positive and negative frequency detuning standing wave field and the atoms can cause a difference in the adjacent peak-to-valley heights of the grating in positive and negative frequency detuning chromium atom lithography,which greatly reduces its accuracy.In this study,we performed a controlled variable growth simulation using the semi-classical theoretical model and Monte Carlo method with trajectory tracking and ballistic deposition methods to investigate the influence of key experimental parameters on the surface growth process of positive and negative frequency detuning atomic lithography gratings.We established a theoretical model based on simulation results and summarized empirical equations to guide the selection of experimental parameters.Our simulations achieved uniform positive and negative frequency detuning atomic lithography gratings with a period of 1/4 of the wavelength corresponding to the atomic transition frequency,and adjacent peak-to-valley heights differing by no more than 2 nm,providing an important theoretical reference for the controllable fabrication of these gratings.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11064002 and 11061011)
文摘The characteristics of neutral chromium atoms in the standing wave field are discussed. Based on a semi-classical model, the motion equation of neutral atoms in the laser standing wave field is analyzed, and the trajectories of the atoms are obtained by simulations with the different divergence angles of the atomic beam. The simulation results show that the full width at half maximum (FWHM) of the stripe is 2.75 nm and the contrast is 38.5 : 1 when the divergence angle equals 0 mrad, the FWHM is 24.1 nm and the contrast is 6.8:1 when the divergence angle equals 0.2 mrad and the FWHMs are 58.6 and 137.8 nm, and the contrasts are 3.3 : 1 and 1.6 : i when the divergence angles equal 0.5 and 1.0 mrad, respectively.
基金Project supported by the Shanghai Nanoscience Foundation,China (Grant Nos.0852nm07000 and 0952nm07000)the National Natural Science Foundation of China (Grant Nos.10804084 and 91123022)+1 种基金the National Key Technology R&D Program,China (Grant No.2006BAF06B08)the Specialized Research Fund for the Doctoral Program of Ministry of High Education of China (Grant No.200802471008)
文摘The use of the dipole force on atoms is a new technology that is used to build nanostructures. In this way, a high quality standard nano-grating can be obtained. Based on the semi-classical model, the motion equation is investigated and the trajectories of atoms in double half Gaussian standing wave field are simulated. Compared with the Gaussian standing wave field, the double half Gaussian standing wave can well focus the Cr atoms. In order to obtain this kind of beam, a prism is designed and the experimental result shows that the beam is well generated.
基金supported by the Major Research Plan of the National Natural Science Foundation of China(Grant No.91123022)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.10804084)
文摘Atom lithography with chromium can be utilized to fabricate a pitch standard, which is chrectly traceable to me wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrates that the pitch standard is (212.8±0.1) nm with a peak-to-valley-height (PTVH) better than 20 nm. The measurement results show the high period accuracy of traceability with the standing laser wavelength (λ/2 = 212.78 nm). The Cr nano-grating covers a 1000μm×500 μm area, with a PTVH better than 10 nm. The feature width broadening of the Cr nanostructure has been experimentally observed along the direction of the standing waves. The PTVH along the Gaussian laser direction is similar to a Gaussian distribution. Highly uniform periodic nanostructures with a big area at the millimeter scale, and the surface growth uniformity of the Cr nano-grating, show its great potential in the application of a traceable pitch standard at trans-scales.
基金The authors thank Professor C.N.R.Rao,Fellow of Royal Society(FRS)for his encouragement.Support from the Department of Science and Technology,Government of India is gratefully acknowledged.N.K.acknowledges Council of Scientific and Industrial Research(CSIR)for funding.N.K.acknowledges Ritu for reading the manuscript.The authors thank Veeco India Nano-technology Laboratory at Jawaharlal Nehru Centre for Advanced Scientific Research(JNCASR)for the AFM facility.A.S.acknowledges INDO-US Science&Technology Forum(IUSSTF)for funding.
文摘Working with a biased atomic force microscope(AFM)tip in the tapping mode under ambient atmosphere,attoliter(10^(-18) L)water droplet patterns have been generated on a patterned carbonaceous surface.This is essentially electrocondensation of water leading to charged droplets,as evidenced from electrostatic force microscopy measurements.The droplets are unusual in that they exhibit a highly corrugated surface and evaporate rather slowly,taking several tens of minutes.