Dip-pen nanolithography is a new scanning probe lithography (SPL) technique based on atomic force microscopy (AFM), and now has made a great progress. The process of dip-pen lithography involves the adsorption of ink ...Dip-pen nanolithography is a new scanning probe lithography (SPL) technique based on atomic force microscopy (AFM), and now has made a great progress. The process of dip-pen lithography involves the adsorption of ink molecules on AFM tip, the formation of water meniscus, the transport of ink molecules, and diffusion of ink molecules on the substrate. More factors such as temperature, humidity, tip, scanning speed and so on will influence the process of dip-pen lithography. The paper analyzes in detail the mechanism of this technique, introduces synthetically the latest development, including electrochemical DPN, more-mode DPN, multiple DPN, multi-probe array DPN and so on. Finally, the paper describes the characteristics and the application of DPN.展开更多
Femtosecond laser ablation-driven periodic surface structuring offers a promising method for large-scale and high-throughput nanolithography technique.However,the self-organized periodic structures typically manifest ...Femtosecond laser ablation-driven periodic surface structuring offers a promising method for large-scale and high-throughput nanolithography technique.However,the self-organized periodic structures typically manifest constraints in terms of tunable period and depth,as well as suboptimal regularity,which restricts their broader application potential.Here,in terms of a rarely explored laser-induced photochemical mechanism for nonablative structuring,we demonstrate manufacturing of sub-wavelength oxidative grating structures on silicon films with active structural modulation.In this scenario,the plasmonic field plays a pivotal role in dragging oxygen ions from surface into the silicon,greatly speeding up oxidation rates.While high oxygen doping levels can already be achieved with single-pulse exposure,far superior results are obtained with the application of 40-MHz burst mode pulse trains,mitigating the formation of excessively large nanocrystallites.Furthermore,it is revealed that the periodicity and modulation depth of laser-writing nanograting are both dependent on the number of pulse per burst.This offers a convenient scheme for actively controlling laser plasmonic lithography.展开更多
Nanolithography plays crucial roles in the miniaturization of dense integrated circuit,which extremely depends on innovative resist materials.Recently,metal-containing resists have been explored due to their higher sh...Nanolithography plays crucial roles in the miniaturization of dense integrated circuit,which extremely depends on innovative resist materials.Recently,metal-containing resists have been explored due to their higher short-wavelength photon absorption than traditional polymer resists.Herein,for the first time,the patterning performance of non-alkyl tin-oxo clusters has been evaluated.Meanwhile,the influence of structural characteristics on resolution and sensitivity has been investigated.To evaluate the surface ligand effect,three non-alkyl Sn_(10)-oxo clusters with the same core were functionalized with pyrazole,3-methylpyrazole and 4-methylpyrazole,respectively.Furthermore,another Sn_(14)-oxo cluster with similar core configuration was also prepared using 4-methylpyrazole ligand to study the influence of Sn nuclearity.Spin-coating method was then applied to fabricate thin films of these non-alkyl tin-oxo clusters on Si substrate,which showed various thicknesses and roughnesses.More interestingly,electron beam lithography(EBL)patterning studies indicated that for the same Sn_(10)core,the 4-methylpyrazoledecorated clusters showed the best performance.As for the different cluster cores with the same 4-methylpyrazole ligand,the patterns of Sn_(10)with the higher ligand:Sn ratio are also better than those of Sn_(14).Finally,distinguishable 50 nm resolution was achieved by 4-methylpyrazole-decorated Sn_(10)at expose energy of 100μC/cm2which can be significantly improved by increasing expose energy to 1,000μC/cm2as confirmed by atomic force microscopy(AFM)images.This work not only opens the nanolithography applications of non-alkyl tin-oxo clusters,but also provides an effective structural methodology for improving their patterning performance in future.展开更多
A fiber-based source that can be exploited in a stimulated emission depletion(STED) inspired nanolithography setup is presented.Such a source maintains the excitation beam pulse, generates a ring-shaped depletion beam...A fiber-based source that can be exploited in a stimulated emission depletion(STED) inspired nanolithography setup is presented.Such a source maintains the excitation beam pulse, generates a ring-shaped depletion beam, and automatically realizes dual-beam coaxial alignment that is critical for two beam nanolithography.The mode conversion of the depletion beam is realized by using a customized vortex fiber, which converts the Gaussian beam into a donut-shaped azimuthally polarized beam.The pulse width and repetition frequency of the excitation beam remain unchanged, and its polarization states can be controlled.According to the simulated point spread function of each beam in the focal region, the full width at half-maximum of the effective spot size in STED nanofabrication could decrease to less than 28.6 nm.展开更多
Dip-pen na.nolithography （DPN） is a useful method for directly printing materials on surfaces with sub-50nm resolution. Because it, involves the physical transport of materials from a scanning probe tip to a surface...Dip-pen na.nolithography （DPN） is a useful method for directly printing materials on surfaces with sub-50nm resolution. Because it, involves the physical transport of materials from a scanning probe tip to a surface and the subsequent chemical interaction of that material with the surface, there are many factors to consider when attempting to understand DPN. In this review, we overview the physical and chemical processes that are known to play a role in DPN, Through a detailed review of the literature, we classify inks into three general categories based on their transport properties, and highlight the myriad ways that. DPN can be used to perform chemistry at the tip of a scanning probe.展开更多
Nanolithography is a patterning technique for the fabrication of nano-scale structures.A promising method of nanolithography known as scanning probe lithography has particularly extensive applications for its high res...Nanolithography is a patterning technique for the fabrication of nano-scale structures.A promising method of nanolithography known as scanning probe lithography has particularly extensive applications for its high resolution,high reliability,and simple operation.In this paper,a novel electrothermally actuated cantilever with integrated heater,thermal conductor and actuator for scanning probe lithography is proposed.Cantilevers are designed in an 8×4 array.Analytical models are presented to simulate the temperature distribution,deflection and thermal crosstalk of the cantilever array.This structure is successfully fabricated.It is demonstrated that this structure can produce a tip deflection of 16.9μm at an actuation current of 5.5 mA and the thermal crosstalk between the cantilevers is neglected.展开更多
Free-space diffractive neural networks(DNNs)have been an intense research topic in machine learning for image recognition and encryption due to their high speed,lower power consumption,and high neuron density.Recent a...Free-space diffractive neural networks(DNNs)have been an intense research topic in machine learning for image recognition and encryption due to their high speed,lower power consumption,and high neuron density.Recent advances in DNNs have highlighted the need for smaller device footprints and the shift toward visible wavelengths.However,DNNs fabricated by electron beam lithography,are not suitable for microscopic imaging applications due to their large sizes,and DNNs fabricated by two-photon nanolithography with cylindrical neurons are not optimal for visible wavelengths,as the highorder diffraction could induce low diffraction efficiency.In this paper,we demonstrate that cubical diffraction neurons are more efficient diffraction elements for DNNs compared with cylindrical neurons.Based on the theoretical analysis of the relationship between the detector area sizes and classification accuracy,we reduced the size of DNNs operating at the wavelength of 532 nm for handwritten digit classification to micrometer scale by two-photon nanolithography.The DNNs with cubical neurons demonstrated an experimental classification accuracy(89.3%)for single-layer DNN,and 83.3%for two-layer DNN with device sizes similar to that of biological cells(about 100μm×100μm).Our results paved the pathway to integrate 3D micrometer-scale DNNs with microscopic imaging systems for biological imaging and cell recognition.展开更多
DNA origami-assisted nanolithography(DOANL)for fabricating custom-designed nanomaterials through pattern transfer from DNA origami to different substrates materials are presented.However,the pattern's integrity an...DNA origami-assisted nanolithography(DOANL)for fabricating custom-designed nanomaterials through pattern transfer from DNA origami to different substrates materials are presented.However,the pattern's integrity and resolution face considerable challenges due to the uncontrollable growth of the nanomaterials during transformation and the unclear mechanism of DOANL.Herein,we report a DOANL combined with area-selective atomic layer deposition(ALD)strategy for fabricating custom shapes hafnium oxide(HfO2)with the high-fidelity and high-throughput.We find that the HfO_(2)selectively grows on DNA origami substrates in a hydroxyl-rich area instead of a methyl-rich protective layer.Combined with the merit of the area-selective ALD method,theHfO_(2)atom selectively coated on the DNA origami surface,thus,precisely modeling the shapes with high-precision in our study based on the surface groups difference of DNA origami and the naked hexamethyldisilane(HMDS)-treated substrates,which reveal the mechanical of high-fidelity pattern transfer based on DOANL.As a result,DNA origami structures can program the shape ofHfO_(2)nanostructures.The DOANL that is based on the principle of"bottom-up"precision assembly breaks through the shape complexity and high-throughput fabrication limitation of theHfO_(2)nanostructures,including two-and three-dimensional structures,plane and curved structures,monolithic and hollow structures.Based on the"top-down"accurate fabrication principle,the area-selective ALD on methyl-rich protective layer substrates improves the integrity and resolution of the pattern transfer process.Overall,this work provides a general technology for nanofabrication strategy.展开更多
Semiconductor quantum dots(QDs),as high-performance materials,play an essential role in contemporary industry,mainly due to their high photoluminescent quantum yield,wide absorption characteristics,and size-dependent ...Semiconductor quantum dots(QDs),as high-performance materials,play an essential role in contemporary industry,mainly due to their high photoluminescent quantum yield,wide absorption characteristics,and size-dependent light emission.It is essential to construct well-defined micro-/nano-structures using QDs as building blocks for micro-optic applications.However,the fabrication of stable QDs with designed functional structures has long been challenging.Here,we propose a strategy for three-dimensional direct lithography of desired QDs within a hybrid medium with specific protection properties.The acrylate-functionalized hybrid precursors enable local crosslinking through ultrafast laser-induced multiphoton absorption,achieving sub-100 nm resolution surpassing the diffraction limit.The printed micro-/nano-structures possess thermal stability up to 600℃,which can be transformed to inorganic architectures with a volume shrinkage.Due to the encapsulated QDs within the densely silicon-oxygen molecular networks,the functional structures demonstrate good stability against ultraviolet irradiation,corrosive solutions,and elevated temperatures.Based on hybrid3D nanolithography,bicolor multilayer micro-/nano-structures are manufactured for applications in 3D data storage and optical information encryption.This research presents an effective strategy for the fabrication of desired QD micro-/nano-structures,supporting the development of stable functional device applications.展开更多
The fabrication of nanostructures beyond the diffraction limit has been the focus of nanotechnology research.Scanning probe microscopy(SPM)has attracted the attention of researchers for the detection and manufacture o...The fabrication of nanostructures beyond the diffraction limit has been the focus of nanotechnology research.Scanning probe microscopy(SPM)has attracted the attention of researchers for the detection and manufacture of nanostructures.Here,a nanosecond laser irradiated a cantilevered scanning nearfield optical microscopy(SNOM)tip and directly wrote subwavelength nanostructures on Au nano-film,without the assistance of a mask or vacuum atmosphere.This method was stable and reproducible for long-term use.The in situ morphology detection was conducted after the writing process by atomic force microscope(AFM).A feature linewidth of approximately 83.6 nm(<k/6)was confirmed using scanning electron microscopy(SEM).Linewidth of(167.8±6.6)nm was reproduced stably.Theoretical calculations revealed that the elliptical heat distribution under the SNOM tip generated different linewidths when the tip scanned vertically and horizontally.It also interpreted the influential mechanism of single-pulse energy.The simulated linewidths were consistent with the fabricated linewidths.According to the elemental analysis by energy dispersive spectrometer(EDS),the mechanism of this method can be interpreted asmelting of the Au nano-film instead of oxidation.Owing to its high positioning,machining accuracy,and instantaneous energy,this technology is considered convenient and economical for nanostructure fabrication and is proposed to be applied in nanolithography on multiple materials in the future.展开更多
Ultrasensitive nanomechanical instruments,e.g.atomic force microscopy(AFM),can be used to perform delicate biomechanical measurements and reveal the complex mechanical environment of biological processes.However,these...Ultrasensitive nanomechanical instruments,e.g.atomic force microscopy(AFM),can be used to perform delicate biomechanical measurements and reveal the complex mechanical environment of biological processes.However,these instruments are limited because of their size and complex feedback system.In this study,we demonstrate a miniature fiber optical nanomechanical probe(FONP)that can be used to detect the mechanical properties of single cells and in vivo tissue measurements.A FONP that can operate in air and in liquids was developed by programming a microcantilever probe on the end face of a single-mode fiber using femtosecond laser two-photon polymerization nanolithography.To realize stiffness matching of the FONP and sample,a strategy of customizing the microcantilever’s spring constant according to the sample was proposed based on structure-correlated mechanics.As a proof-of concept,three FONPs with spring constants varying from 0.421 N m^(−1)to 52.6 N m^(−1)by more than two orders of magnitude were prepared.The highest microforce sensitivity was 54.5 nmμN^(−1)and the detection limit was 2.1 nN.The Young’s modulus of heterogeneous soft materials,such as polydimethylsiloxane,muscle tissue of living mice,onion cells,and MCF-7 cells,were successfully measured,which validating the broad applicability of this method.Our strategy provides a universal protocol for directly programming fiber-optic AFMs.Moreover,this method has no special requirements for the size and shape of living biological samples,which is infeasible when using commercial AFMs.FONP has made substantial progress in realizing basic biological discoveries,which may create new biomedical applications that cannot be realized by current AFMs.展开更多
Reliable fabrication of micro/nanostructures with sub-10 nm features is of great significance for advancing nanoscience and nanotechnology.While the capability of current complementary metal-oxide semiconductor(CMOS)c...Reliable fabrication of micro/nanostructures with sub-10 nm features is of great significance for advancing nanoscience and nanotechnology.While the capability of current complementary metal-oxide semiconductor(CMOS)chip manufacturing can produce structures on the sub-10 nm scale,many emerging applications,such as nano-optics,biosensing,and quantum devices,also require ultrasmall features down to single digital nanometers.In these emerging applications,CMOS-based manufacturing methods are currently not feasible or appropriate due to the considerations of usage cost,material compatibility,and exotic features.Therefore,several specific methods have been developed in the past decades for different applications.In this review,we attempt to give a systematic summary on sub-10 nm fabrication methods and their related applications.In the first and second parts,we give a brief introduction of the background of this research topic and explain why sub-10 nm fabrication is interesting from both scientific and technological perspectives.In the third part,we comprehensively summarize the fabrication methods and classify them into three main approaches,including lithographic,mechanics-enabled,and post-trimming processes.The fourth part discusses the applications of these processes in quantum devices,nano-optics,and high-performance sensing.Finally,a perspective is given to discuss the challenges and opportunities associated with this research topic.展开更多
We studied silicon,carbon,and SiC xnanostructures fabricated using liquid-phase electron-beam-induced deposition technology in transmission electron microscopy systems.Nanodots obtained from fixed electron beam irradi...We studied silicon,carbon,and SiC xnanostructures fabricated using liquid-phase electron-beam-induced deposition technology in transmission electron microscopy systems.Nanodots obtained from fixed electron beam irradiation followed a universal size versus beam dose trend,with precursor concentrations from pure Si Cl4to 0%SiC l4in CH2Cl2,and electron beam intensity ranges of two orders of magnitude,showing good controllability of the deposition.Secondary electrons contributed to the determination of the lateral sizes of the nanostructures,while the primary beam appeared to have an effect in reducing the vertical growth rate.These results can be used to generate donut-shaped nanostructures.Using a scanning electron beam,line structures with both branched and unbranched morphologies were also obtained.The liquid-phase electron-beaminduced deposition technology is shown to be an effective tool for advanced nanostructured material generation.展开更多
Optical antennas play an important role in optical field manipulation.Among them,nanoscale bowtie antennas have been extensively studied for its high confinement and enhancement.In this mini-review,we start with a bri...Optical antennas play an important role in optical field manipulation.Among them,nanoscale bowtie antennas have been extensively studied for its high confinement and enhancement.In this mini-review,we start with a brief introduction of bowtie antennas and underlying physics.Then we review the applications with respect to optically and electrically excited nanoscale bowtie antennas.Optically driven bowtie antennas enable a set of optical applications such as near-field imaging/trapping,nonlinear response,nanolithography,photon generation and detection.Finally,we put emphasis on the principle and applications of electrically driven bowtie antennas,an emerging method of generating ultrafast and broadband tunable nanosources.In a word,nanoscale bowtie antennas still have great potential research value to explore.展开更多
Both the cluster chemistry of tin and lanthanides have attracted extensive research interest,showing wide applications in catalysis,magnetism,luminescence,and lithography.However,their fusion into heterometallic Sn-Ln...Both the cluster chemistry of tin and lanthanides have attracted extensive research interest,showing wide applications in catalysis,magnetism,luminescence,and lithography.However,their fusion into heterometallic Sn-Ln oxo clusters is still to be explored.In this study,through the stabilization of alkenyl-type cis-5-norbornene-endo-2,3-dicarboxylic acid(H_(2)NE)ligands,a series of atomically precise Sn-Ln oxo nanoclusters have been successfully constructed from the assembly of heterometallic tetranuclear Sn_(x)Ln((4-x))building blocks.Thereinto,Sn_(12)Eu_(8)and Sn_(13)Er_(6)with the highest nuclearities are built from multiple assembly of 8{Sn_(2)Eu_(2)}units and 6{Sn_(3)Er}and{Sn_(2)Er_(2)}units,respectively.ESI-MS analysis indicates that Sn_(13)Er_(6)has high solution stability,allowing their packing into thin films for lithography applications.As a result of electron beam lithography(EBL)studies,the condensation of Sn_(13)Er_(6)can be triggered by low energy radiation of 10μC/cm^(2),and 50 nm lines have been fabricated at expose energy of 50μC/cm^(2),confirming the satisfying sensitivity and resolution of Sn_(13)Er_(6).Hence,the success of this study develops the chemistry of heterometallic tin-lanthanide clusters that can be applied as novel negative photoresist materials.展开更多
Manipulating materials at the nanometer scale is challenging, particularly if alignment with nanoscale electrodes is desired. Here, we describe a lithography-free, self-aligned nanotrench ablation （SANTA） technique ...Manipulating materials at the nanometer scale is challenging, particularly if alignment with nanoscale electrodes is desired. Here, we describe a lithography-free, self-aligned nanotrench ablation （SANTA） technique to create nanoscale ＂trenches＂ in a polymer like poly（methyl methacrylate） （PMMA）. The nanotrenches are self-aligned with carbon nanotube （CNT） or graphene ribbon electrodes through a simple Joule heating process. Using simulations and experiments we investigated how the Joule power, ambient temperature, PMMA thickness, and substrate properties affect the spatial resolution of this technique. We achieved sub-20 nm nanotrenches, for the first time, by lowering the ambient temperature and reducing the PMMA thickness. We also demonstrated a functioning nanoscale resistive memory （RRAM） bit self- aligned with a CNT control device, achieved through the SANTA approach. This technique provides an elegant and inexpensive method to probe nanoscale devices using self-aligned electrodes, without the use of conventional alignment or lithography steps.展开更多
The broad availability of high throughput nanostructure fabrication is essential for advancement in nanoscale science. Large-scale manufacturing developed by the semiconductor industry is often too resource-intensive ...The broad availability of high throughput nanostructure fabrication is essential for advancement in nanoscale science. Large-scale manufacturing developed by the semiconductor industry is often too resource-intensive for medium scale laboratory prototyping. We demonstrate the inexpensive wafer scale direct- write of Ge and Si nanostructures with a 4-inch mask aligner retrofitted with a conducting microstructured stamp. A bias applied between the stamp and an underlying silicon substrate results in the reaction of diphenylgermane and diphenylsilane precursors at the stamp--substrate interface to yield the direct- write of Ge and Si nanostructures in determined locations. With the increasing number of outdated mask aligners available from the semiconductor industry and an extensive library of liquid precursors, this strategy provides facile, inexpensive, wafer scale semiconductor direct-write for applications such as electronics, photonics, and photovoltaics.展开更多
A simple,inexpensive direct micromolding method for patterning Au nanocrystal superlattices using a polydimethylsiloxane(PDMS)stamp has been developed.The method involves in situ synthesis of Au(I)dodecanethiolate and...A simple,inexpensive direct micromolding method for patterning Au nanocrystal superlattices using a polydimethylsiloxane(PDMS)stamp has been developed.The method involves in situ synthesis of Au(I)dodecanethiolate and its decomposition leading to Au nanocrystals in the microchannels of the stamp which order themselves to form patterned superlattice stripes,in conformity with the stamp geometry.Owing to its insolubility in common solvents,the dodecanethiolate was made by reacting Au(PPh3)Cl and dodecanethiol in situ inside the microchannels,by injecting first the former solution in toluene at room temperature followed by the thiol solution at 120°C.Annealing the reaction mixture at 250°C,resulted in formation of nanocrystals(with a mean diameter of 7.5 nm)and hexagonal ordering.By using an external pressure while molding,parallel stripes with sub-100 nm widths were obtained.The choice of parameters such as injection temperature of the thiol and concentrations is shown to be important if an ordered superlattice is to be obtained.In addition,these parameters can be varied as a means to control the nanocrystal size.展开更多
SiCx nano dots and nano wires with sizes from 60 nm to approximately 2μm were fabricated using liquid cell transmission electron microscope(TEM)technology.A SiCl_(4)in CH_(2)Cl_(2)solution was sealed between two piec...SiCx nano dots and nano wires with sizes from 60 nm to approximately 2μm were fabricated using liquid cell transmission electron microscope(TEM)technology.A SiCl_(4)in CH_(2)Cl_(2)solution was sealed between two pieces of Si_(3)N_(4)window grids in an in situ TEM liquid cell.Focused 200 keV electron beams were used to bombard the sealed precursors,which caused decomposition of the precursor materials,and deposition of the nano materials on the Si_(3)N_(4)window substrates.The size of nano dots increased with beam exposure time,following an approximately exponential relationship with the beam doses.Secondary electrons are attributed as the primary sources for the Si and C reduction.A nano device was formed from a deposited nano wire,with its electrical property characterized.展开更多
SnO_(2)thin-film gas sensors have been successfully fabricated on nanospiked polyurethane polymer surfaces,which are replicated by a low-cost soft nanolithography method from silicon nanospike structures formed with f...SnO_(2)thin-film gas sensors have been successfully fabricated on nanospiked polyurethane polymer surfaces,which are replicated by a low-cost soft nanolithography method from silicon nanospike structures formed with femtosecond laser irradiations.Measurements revealed significant response to carbon monoxide(CO)gas at room temperature,which is considerably different from the sensors of SnO_(2)thin films coated on smooth surfaces that show no response to CO gas at room temperature.The high area/volume ratio and sharp structures of the nanospikes enhance the sensitivity of SnO_(2)at room temperature.This will greatly decrease the electrical power consumption of the gas sensor and the cost for calibrations,and has great potential for application in other sensing systems.展开更多
基金Foundation of Education of Zhejiang Province, China ( No.20060470).
文摘Dip-pen nanolithography is a new scanning probe lithography (SPL) technique based on atomic force microscopy (AFM), and now has made a great progress. The process of dip-pen lithography involves the adsorption of ink molecules on AFM tip, the formation of water meniscus, the transport of ink molecules, and diffusion of ink molecules on the substrate. More factors such as temperature, humidity, tip, scanning speed and so on will influence the process of dip-pen lithography. The paper analyzes in detail the mechanism of this technique, introduces synthetically the latest development, including electrochemical DPN, more-mode DPN, multiple DPN, multi-probe array DPN and so on. Finally, the paper describes the characteristics and the application of DPN.
基金supported by the National Natural Science Foundation of China(12474317 and 62105269).
文摘Femtosecond laser ablation-driven periodic surface structuring offers a promising method for large-scale and high-throughput nanolithography technique.However,the self-organized periodic structures typically manifest constraints in terms of tunable period and depth,as well as suboptimal regularity,which restricts their broader application potential.Here,in terms of a rarely explored laser-induced photochemical mechanism for nonablative structuring,we demonstrate manufacturing of sub-wavelength oxidative grating structures on silicon films with active structural modulation.In this scenario,the plasmonic field plays a pivotal role in dragging oxygen ions from surface into the silicon,greatly speeding up oxidation rates.While high oxygen doping levels can already be achieved with single-pulse exposure,far superior results are obtained with the application of 40-MHz burst mode pulse trains,mitigating the formation of excessively large nanocrystallites.Furthermore,it is revealed that the periodicity and modulation depth of laser-writing nanograting are both dependent on the number of pulse per burst.This offers a convenient scheme for actively controlling laser plasmonic lithography.
基金supported by the National Natural Science Foundation of China(21922111,91961108)。
文摘Nanolithography plays crucial roles in the miniaturization of dense integrated circuit,which extremely depends on innovative resist materials.Recently,metal-containing resists have been explored due to their higher short-wavelength photon absorption than traditional polymer resists.Herein,for the first time,the patterning performance of non-alkyl tin-oxo clusters has been evaluated.Meanwhile,the influence of structural characteristics on resolution and sensitivity has been investigated.To evaluate the surface ligand effect,three non-alkyl Sn_(10)-oxo clusters with the same core were functionalized with pyrazole,3-methylpyrazole and 4-methylpyrazole,respectively.Furthermore,another Sn_(14)-oxo cluster with similar core configuration was also prepared using 4-methylpyrazole ligand to study the influence of Sn nuclearity.Spin-coating method was then applied to fabricate thin films of these non-alkyl tin-oxo clusters on Si substrate,which showed various thicknesses and roughnesses.More interestingly,electron beam lithography(EBL)patterning studies indicated that for the same Sn_(10)core,the 4-methylpyrazoledecorated clusters showed the best performance.As for the different cluster cores with the same 4-methylpyrazole ligand,the patterns of Sn_(10)with the higher ligand:Sn ratio are also better than those of Sn_(14).Finally,distinguishable 50 nm resolution was achieved by 4-methylpyrazole-decorated Sn_(10)at expose energy of 100μC/cm2which can be significantly improved by increasing expose energy to 1,000μC/cm2as confirmed by atomic force microscopy(AFM)images.This work not only opens the nanolithography applications of non-alkyl tin-oxo clusters,but also provides an effective structural methodology for improving their patterning performance in future.
基金supported by the National Natural Science Foundation of China (No.61805142)the Shanghai Science and Technology Committee (No.19060502500)the Natural Science Foundation of Shanghai (No.20ZR1437600)。
文摘A fiber-based source that can be exploited in a stimulated emission depletion(STED) inspired nanolithography setup is presented.Such a source maintains the excitation beam pulse, generates a ring-shaped depletion beam, and automatically realizes dual-beam coaxial alignment that is critical for two beam nanolithography.The mode conversion of the depletion beam is realized by using a customized vortex fiber, which converts the Gaussian beam into a donut-shaped azimuthally polarized beam.The pulse width and repetition frequency of the excitation beam remain unchanged, and its polarization states can be controlled.According to the simulated point spread function of each beam in the focal region, the full width at half-maximum of the effective spot size in STED nanofabrication could decrease to less than 28.6 nm.
基金Acknowledgements C.A.M. acknowledges the U. S. Air Force Office of Scientific Research （AFOSR, Awards FA9550-12-1-0280 and FA9550-12-1-0141）, the Defense Advanced Research Projects Agency （DARPA, Award N66001-08-1-2044） and the National Science Foundation （NSF, Awards DBI-1152139 and DMB-1124131） for support of this research. K. A. B. and X. L. gratefully acknowledges support from Northwestern University＇s International Institute for Nanotechnology. D. J. E. acknowledges the DoD and AFOSR for a National Defense Science and Engineering Graduate （NDSEG） Fellowship, 32 CFR 168a.
文摘Dip-pen na.nolithography （DPN） is a useful method for directly printing materials on surfaces with sub-50nm resolution. Because it, involves the physical transport of materials from a scanning probe tip to a surface and the subsequent chemical interaction of that material with the surface, there are many factors to consider when attempting to understand DPN. In this review, we overview the physical and chemical processes that are known to play a role in DPN, Through a detailed review of the literature, we classify inks into three general categories based on their transport properties, and highlight the myriad ways that. DPN can be used to perform chemistry at the tip of a scanning probe.
基金supported by the National Natural Science Foundation of China (Grant No.60576053)Hi-Tech Research and Development Program of China (Grant No.2007AA03Z333)
文摘Nanolithography is a patterning technique for the fabrication of nano-scale structures.A promising method of nanolithography known as scanning probe lithography has particularly extensive applications for its high resolution,high reliability,and simple operation.In this paper,a novel electrothermally actuated cantilever with integrated heater,thermal conductor and actuator for scanning probe lithography is proposed.Cantilevers are designed in an 8×4 array.Analytical models are presented to simulate the temperature distribution,deflection and thermal crosstalk of the cantilever array.This structure is successfully fabricated.It is demonstrated that this structure can produce a tip deflection of 16.9μm at an actuation current of 5.5 mA and the thermal crosstalk between the cantilevers is neglected.
基金supported by the National Key Research and Development Program of China(Nos.2021YFB2802000 and 2022YFB2804301)the Science and Technology Commission of Shanghai Municipality(No.21DZ1100500)+4 种基金the Shanghai Municipal Science and Technology Major Project,the Shanghai Frontiers Science Center Program(2021–2025 No.20)the National Natural Science Foundation of China(Nos.61975123,62305219,and 62205208)the Shanghai Natural Science Foundation(No.23ZR1443200)the China Postdoctoral Science Foundation(Nos.2022M712138 and 2021M702192)the Shanghai Super Postdoctoral Incentive Scheme(Nos.5B22904002 and 5B22904006)。
文摘Free-space diffractive neural networks(DNNs)have been an intense research topic in machine learning for image recognition and encryption due to their high speed,lower power consumption,and high neuron density.Recent advances in DNNs have highlighted the need for smaller device footprints and the shift toward visible wavelengths.However,DNNs fabricated by electron beam lithography,are not suitable for microscopic imaging applications due to their large sizes,and DNNs fabricated by two-photon nanolithography with cylindrical neurons are not optimal for visible wavelengths,as the highorder diffraction could induce low diffraction efficiency.In this paper,we demonstrate that cubical diffraction neurons are more efficient diffraction elements for DNNs compared with cylindrical neurons.Based on the theoretical analysis of the relationship between the detector area sizes and classification accuracy,we reduced the size of DNNs operating at the wavelength of 532 nm for handwritten digit classification to micrometer scale by two-photon nanolithography.The DNNs with cubical neurons demonstrated an experimental classification accuracy(89.3%)for single-layer DNN,and 83.3%for two-layer DNN with device sizes similar to that of biological cells(about 100μm×100μm).Our results paved the pathway to integrate 3D micrometer-scale DNNs with microscopic imaging systems for biological imaging and cell recognition.
基金supported by the National Key R&D Program of China(No.2019YFA0905800)the National Natural Science Foundation of China(No.21705048)+5 种基金Guangdong Basic and Applied Basic Research Foundation(No.2021A1515012333)Natural Science Foundation of Jiangxi Province(No.20192ACBL20046)the Fundamental Research Funds for the Central Universities(No.20720200004)the Key Project of College Youth Natural Fund of Fujian Province(No.JZ160404)the Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province(No.2020B1212060077)support from Qingdao XINO Tech company.Thanks to Yange Wang for his help in AFM scanning。
文摘DNA origami-assisted nanolithography(DOANL)for fabricating custom-designed nanomaterials through pattern transfer from DNA origami to different substrates materials are presented.However,the pattern's integrity and resolution face considerable challenges due to the uncontrollable growth of the nanomaterials during transformation and the unclear mechanism of DOANL.Herein,we report a DOANL combined with area-selective atomic layer deposition(ALD)strategy for fabricating custom shapes hafnium oxide(HfO2)with the high-fidelity and high-throughput.We find that the HfO_(2)selectively grows on DNA origami substrates in a hydroxyl-rich area instead of a methyl-rich protective layer.Combined with the merit of the area-selective ALD method,theHfO_(2)atom selectively coated on the DNA origami surface,thus,precisely modeling the shapes with high-precision in our study based on the surface groups difference of DNA origami and the naked hexamethyldisilane(HMDS)-treated substrates,which reveal the mechanical of high-fidelity pattern transfer based on DOANL.As a result,DNA origami structures can program the shape ofHfO_(2)nanostructures.The DOANL that is based on the principle of"bottom-up"precision assembly breaks through the shape complexity and high-throughput fabrication limitation of theHfO_(2)nanostructures,including two-and three-dimensional structures,plane and curved structures,monolithic and hollow structures.Based on the"top-down"accurate fabrication principle,the area-selective ALD on methyl-rich protective layer substrates improves the integrity and resolution of the pattern transfer process.Overall,this work provides a general technology for nanofabrication strategy.
基金supported by the National Key Research and Development Program of China(2024YFB3213700)Shenzhen Science and Technology Program(Shenzhen Key Laboratory of Ultrafast Laser Micro/Nano Manufacturing ZDSYS20220606100405013)+3 种基金Natural Science Foundation of Guangdong Province(2022B1515120061)National Natural Science Foundation of China(T2421003)Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZC20231722)Research Team Cultivation Program of Shenzhen University(2023QNT009)。
文摘Semiconductor quantum dots(QDs),as high-performance materials,play an essential role in contemporary industry,mainly due to their high photoluminescent quantum yield,wide absorption characteristics,and size-dependent light emission.It is essential to construct well-defined micro-/nano-structures using QDs as building blocks for micro-optic applications.However,the fabrication of stable QDs with designed functional structures has long been challenging.Here,we propose a strategy for three-dimensional direct lithography of desired QDs within a hybrid medium with specific protection properties.The acrylate-functionalized hybrid precursors enable local crosslinking through ultrafast laser-induced multiphoton absorption,achieving sub-100 nm resolution surpassing the diffraction limit.The printed micro-/nano-structures possess thermal stability up to 600℃,which can be transformed to inorganic architectures with a volume shrinkage.Due to the encapsulated QDs within the densely silicon-oxygen molecular networks,the functional structures demonstrate good stability against ultraviolet irradiation,corrosive solutions,and elevated temperatures.Based on hybrid3D nanolithography,bicolor multilayer micro-/nano-structures are manufactured for applications in 3D data storage and optical information encryption.This research presents an effective strategy for the fabrication of desired QD micro-/nano-structures,supporting the development of stable functional device applications.
基金supported by the National Key Research and Development Program of China(2023YFB4605100)the Shaanxi Provincial Key Research and Development Program(2019ZDLGY01-09 and 2021ZDLGY10-02)the State Key Laboratory of Solidification Processing(SKLSP202203).
文摘The fabrication of nanostructures beyond the diffraction limit has been the focus of nanotechnology research.Scanning probe microscopy(SPM)has attracted the attention of researchers for the detection and manufacture of nanostructures.Here,a nanosecond laser irradiated a cantilevered scanning nearfield optical microscopy(SNOM)tip and directly wrote subwavelength nanostructures on Au nano-film,without the assistance of a mask or vacuum atmosphere.This method was stable and reproducible for long-term use.The in situ morphology detection was conducted after the writing process by atomic force microscope(AFM).A feature linewidth of approximately 83.6 nm(<k/6)was confirmed using scanning electron microscopy(SEM).Linewidth of(167.8±6.6)nm was reproduced stably.Theoretical calculations revealed that the elliptical heat distribution under the SNOM tip generated different linewidths when the tip scanned vertically and horizontally.It also interpreted the influential mechanism of single-pulse energy.The simulated linewidths were consistent with the fabricated linewidths.According to the elemental analysis by energy dispersive spectrometer(EDS),the mechanism of this method can be interpreted asmelting of the Au nano-film instead of oxidation.Owing to its high positioning,machining accuracy,and instantaneous energy,this technology is considered convenient and economical for nanostructure fabrication and is proposed to be applied in nanolithography on multiple materials in the future.
基金supported by the National Natural Science Foundation of China(NSFC)(62122057,62075136,62175165)Natural Science Foundation of Guangdong Province(2022B1515120061,2019B1515120042)Science and Technology Innovation Commission of Shenzhen(RCYX20200714114524139,JCYJ20200109114001806).
文摘Ultrasensitive nanomechanical instruments,e.g.atomic force microscopy(AFM),can be used to perform delicate biomechanical measurements and reveal the complex mechanical environment of biological processes.However,these instruments are limited because of their size and complex feedback system.In this study,we demonstrate a miniature fiber optical nanomechanical probe(FONP)that can be used to detect the mechanical properties of single cells and in vivo tissue measurements.A FONP that can operate in air and in liquids was developed by programming a microcantilever probe on the end face of a single-mode fiber using femtosecond laser two-photon polymerization nanolithography.To realize stiffness matching of the FONP and sample,a strategy of customizing the microcantilever’s spring constant according to the sample was proposed based on structure-correlated mechanics.As a proof-of concept,three FONPs with spring constants varying from 0.421 N m^(−1)to 52.6 N m^(−1)by more than two orders of magnitude were prepared.The highest microforce sensitivity was 54.5 nmμN^(−1)and the detection limit was 2.1 nN.The Young’s modulus of heterogeneous soft materials,such as polydimethylsiloxane,muscle tissue of living mice,onion cells,and MCF-7 cells,were successfully measured,which validating the broad applicability of this method.Our strategy provides a universal protocol for directly programming fiber-optic AFMs.Moreover,this method has no special requirements for the size and shape of living biological samples,which is infeasible when using commercial AFMs.FONP has made substantial progress in realizing basic biological discoveries,which may create new biomedical applications that cannot be realized by current AFMs.
基金supported by the National Natural Science Foundation of China(Grants Nos.51722503,51805160and U1930114)the National Key Research and Development Program of China(Grant No.2018YFE0109200)the Guangdong Basic Research Foundation(Grant No.2020A1515110971)。
文摘Reliable fabrication of micro/nanostructures with sub-10 nm features is of great significance for advancing nanoscience and nanotechnology.While the capability of current complementary metal-oxide semiconductor(CMOS)chip manufacturing can produce structures on the sub-10 nm scale,many emerging applications,such as nano-optics,biosensing,and quantum devices,also require ultrasmall features down to single digital nanometers.In these emerging applications,CMOS-based manufacturing methods are currently not feasible or appropriate due to the considerations of usage cost,material compatibility,and exotic features.Therefore,several specific methods have been developed in the past decades for different applications.In this review,we attempt to give a systematic summary on sub-10 nm fabrication methods and their related applications.In the first and second parts,we give a brief introduction of the background of this research topic and explain why sub-10 nm fabrication is interesting from both scientific and technological perspectives.In the third part,we comprehensively summarize the fabrication methods and classify them into three main approaches,including lithographic,mechanics-enabled,and post-trimming processes.The fourth part discusses the applications of these processes in quantum devices,nano-optics,and high-performance sensing.Finally,a perspective is given to discuss the challenges and opportunities associated with this research topic.
基金supported by the U.S.Department of Energy under grants DE-FG02-07ER46453 and DEFG02-07ER46471supports from the Shanghai Leading Academic Discipline Project(B502)+4 种基金the Shanghai Key Laboratory Project(08DZ2230500)the Science and Technology Commission of Shanghai Municipality(11nm0507000)the State Key Laboratory of Functional Materials for Informatics Open Project(SKL201306)the Shanghai Pujiang Program(13PJ1401700)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry are highly acknowledged
文摘We studied silicon,carbon,and SiC xnanostructures fabricated using liquid-phase electron-beam-induced deposition technology in transmission electron microscopy systems.Nanodots obtained from fixed electron beam irradiation followed a universal size versus beam dose trend,with precursor concentrations from pure Si Cl4to 0%SiC l4in CH2Cl2,and electron beam intensity ranges of two orders of magnitude,showing good controllability of the deposition.Secondary electrons contributed to the determination of the lateral sizes of the nanostructures,while the primary beam appeared to have an effect in reducing the vertical growth rate.These results can be used to generate donut-shaped nanostructures.Using a scanning electron beam,line structures with both branched and unbranched morphologies were also obtained.The liquid-phase electron-beaminduced deposition technology is shown to be an effective tool for advanced nanostructured material generation.
基金This work is supported by National Key Research and Development Program of China(2018YFB2200900)the Key R&D Program of Anhui(Grant No.202004A05020077)National Natural Science Foundation of China(61775206).The nanofabrication was carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.We also thank Prof.Xianfan Xu of Purdue University for his warm-hearted discussion.
文摘Optical antennas play an important role in optical field manipulation.Among them,nanoscale bowtie antennas have been extensively studied for its high confinement and enhancement.In this mini-review,we start with a brief introduction of bowtie antennas and underlying physics.Then we review the applications with respect to optically and electrically excited nanoscale bowtie antennas.Optically driven bowtie antennas enable a set of optical applications such as near-field imaging/trapping,nonlinear response,nanolithography,photon generation and detection.Finally,we put emphasis on the principle and applications of electrically driven bowtie antennas,an emerging method of generating ultrafast and broadband tunable nanosources.In a word,nanoscale bowtie antennas still have great potential research value to explore.
基金supported by the National Natural Science Foundation of China(21922111,91961108,21935010,22271284)。
文摘Both the cluster chemistry of tin and lanthanides have attracted extensive research interest,showing wide applications in catalysis,magnetism,luminescence,and lithography.However,their fusion into heterometallic Sn-Ln oxo clusters is still to be explored.In this study,through the stabilization of alkenyl-type cis-5-norbornene-endo-2,3-dicarboxylic acid(H_(2)NE)ligands,a series of atomically precise Sn-Ln oxo nanoclusters have been successfully constructed from the assembly of heterometallic tetranuclear Sn_(x)Ln((4-x))building blocks.Thereinto,Sn_(12)Eu_(8)and Sn_(13)Er_(6)with the highest nuclearities are built from multiple assembly of 8{Sn_(2)Eu_(2)}units and 6{Sn_(3)Er}and{Sn_(2)Er_(2)}units,respectively.ESI-MS analysis indicates that Sn_(13)Er_(6)has high solution stability,allowing their packing into thin films for lithography applications.As a result of electron beam lithography(EBL)studies,the condensation of Sn_(13)Er_(6)can be triggered by low energy radiation of 10μC/cm^(2),and 50 nm lines have been fabricated at expose energy of 50μC/cm^(2),confirming the satisfying sensitivity and resolution of Sn_(13)Er_(6).Hence,the success of this study develops the chemistry of heterometallic tin-lanthanide clusters that can be applied as novel negative photoresist materials.
基金We thank Dr. Eilam Yalon and Dr. Ilya Karpov for technical support and helpful discussions. We acknowledge partial support from the National Science Foundation （NSF） CAREER grant 1430530, SRC/Intel grant 2014-IN-2532, the Stanford SystemX Alliance, and the Stanford Nano- and Quantum Science and Engineering （NQSE） Postdoctoral Fellowship （F. X.）.
文摘Manipulating materials at the nanometer scale is challenging, particularly if alignment with nanoscale electrodes is desired. Here, we describe a lithography-free, self-aligned nanotrench ablation （SANTA） technique to create nanoscale ＂trenches＂ in a polymer like poly（methyl methacrylate） （PMMA）. The nanotrenches are self-aligned with carbon nanotube （CNT） or graphene ribbon electrodes through a simple Joule heating process. Using simulations and experiments we investigated how the Joule power, ambient temperature, PMMA thickness, and substrate properties affect the spatial resolution of this technique. We achieved sub-20 nm nanotrenches, for the first time, by lowering the ambient temperature and reducing the PMMA thickness. We also demonstrated a functioning nanoscale resistive memory （RRAM） bit self- aligned with a CNT control device, achieved through the SANTA approach. This technique provides an elegant and inexpensive method to probe nanoscale devices using self-aligned electrodes, without the use of conventional alignment or lithography steps.
文摘The broad availability of high throughput nanostructure fabrication is essential for advancement in nanoscale science. Large-scale manufacturing developed by the semiconductor industry is often too resource-intensive for medium scale laboratory prototyping. We demonstrate the inexpensive wafer scale direct- write of Ge and Si nanostructures with a 4-inch mask aligner retrofitted with a conducting microstructured stamp. A bias applied between the stamp and an underlying silicon substrate results in the reaction of diphenylgermane and diphenylsilane precursors at the stamp--substrate interface to yield the direct- write of Ge and Si nanostructures in determined locations. With the increasing number of outdated mask aligners available from the semiconductor industry and an extensive library of liquid precursors, this strategy provides facile, inexpensive, wafer scale semiconductor direct-write for applications such as electronics, photonics, and photovoltaics.
基金Support from the Department of Science and Technology,India is gratefully acknowledgedB.R.thanks council for Scientific and Industrial Research(CSIR),India for financial assistance.
文摘A simple,inexpensive direct micromolding method for patterning Au nanocrystal superlattices using a polydimethylsiloxane(PDMS)stamp has been developed.The method involves in situ synthesis of Au(I)dodecanethiolate and its decomposition leading to Au nanocrystals in the microchannels of the stamp which order themselves to form patterned superlattice stripes,in conformity with the stamp geometry.Owing to its insolubility in common solvents,the dodecanethiolate was made by reacting Au(PPh3)Cl and dodecanethiol in situ inside the microchannels,by injecting first the former solution in toluene at room temperature followed by the thiol solution at 120°C.Annealing the reaction mixture at 250°C,resulted in formation of nanocrystals(with a mean diameter of 7.5 nm)and hexagonal ordering.By using an external pressure while molding,parallel stripes with sub-100 nm widths were obtained.The choice of parameters such as injection temperature of the thiol and concentrations is shown to be important if an ordered superlattice is to be obtained.In addition,these parameters can be varied as a means to control the nanocrystal size.
基金The experiments have been carried out in part in the Frederick Seitz Materials Research Laboratory Central Facilities,University of Illinois,which are partially supported by the U.S.Department of Energy under grants DE-FG02-07ER46453 and DE-FG02-07ER46471The authors thank S.J.Dillon,Y.Liu,J.Mabon,K.-W.Noh,A.Shah,T.Shang,J.G.Wen,J.M.Zuo for the kind help.The project was supported by Shanghai Leading Academic Discipline Project(B502)+2 种基金Shanghai Key Laboratory Project(08DZ2230500)Fundamental Research Fund of ECUST,Science and Technology Commission of Shanghai Municipality Project(11nm0507000)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry.
文摘SiCx nano dots and nano wires with sizes from 60 nm to approximately 2μm were fabricated using liquid cell transmission electron microscope(TEM)technology.A SiCl_(4)in CH_(2)Cl_(2)solution was sealed between two pieces of Si_(3)N_(4)window grids in an in situ TEM liquid cell.Focused 200 keV electron beams were used to bombard the sealed precursors,which caused decomposition of the precursor materials,and deposition of the nano materials on the Si_(3)N_(4)window substrates.The size of nano dots increased with beam exposure time,following an approximately exponential relationship with the beam doses.Secondary electrons are attributed as the primary sources for the Si and C reduction.A nano device was formed from a deposited nano wire,with its electrical property characterized.
基金supported by National Science Foundation under Grant No.1031111.
文摘SnO_(2)thin-film gas sensors have been successfully fabricated on nanospiked polyurethane polymer surfaces,which are replicated by a low-cost soft nanolithography method from silicon nanospike structures formed with femtosecond laser irradiations.Measurements revealed significant response to carbon monoxide(CO)gas at room temperature,which is considerably different from the sensors of SnO_(2)thin films coated on smooth surfaces that show no response to CO gas at room temperature.The high area/volume ratio and sharp structures of the nanospikes enhance the sensitivity of SnO_(2)at room temperature.This will greatly decrease the electrical power consumption of the gas sensor and the cost for calibrations,and has great potential for application in other sensing systems.
