The copolymers of chloroethyl methacrylate (CMA), glycidyl methacrylate (GMA), and methyl methacrylate (MMA) were synthesized in benzene solution. Their breadths of the molecular weight distributions are 2.1 and 2.3,...The copolymers of chloroethyl methacrylate (CMA), glycidyl methacrylate (GMA), and methyl methacrylate (MMA) were synthesized in benzene solution. Their breadths of the molecular weight distributions are 2.1 and 2.3, respectively. The thermal stability of P(GMA-CMA) is superior to that of P(CMA-MMA). The resolutions of P(CMA-MMA) and P(GMA-CMA) photoresists were found to be 0.1-0.16 mu m and 0.17-0.2 mu m, respectively. (Author abstract) 9 Refs.展开更多
Photoresists are radiation-sensitive materials used for forming patterns to build up IC devices.To date,most photoresists have been based on organic polymers,which have been dominating the semiconductor industries ove...Photoresists are radiation-sensitive materials used for forming patterns to build up IC devices.To date,most photoresists have been based on organic polymers,which have been dominating the semiconductor industries over the past few decades.It is obvious that extreme ultraviolet(EUV)lithography has become the next-generation lithography technology.The development of comprehensive performance EUV resist is one of the most critical issues.However,organic polymeric photoresists are difficult to meet the harsh requirements of EUV lithography.Pure inorganic photoresists such as metal salts,hydrogen silsesquioxane(HSQ)are expected for EUV lithography due to their high resistance and high resolution.But the low sensitivity makes them not suitable for high volume manufacturing(HVM).Organic-inorganic hybrid photoresists,containing both organic and inorganic components,are regarded as one of the most promising EUV resists.They combine both merits of organic and inorganic materials and have significant advantages in machinability,etching resistance,EUV absorption,and chemical/thermal stability.Organic-inorganic hybrid photoresists are considered as ideal materials for realizing industrialgrade patterns below 10 nm.This review mainly focuses on the development of organic-inorganic hybrid photoresists over the past decade.展开更多
Epoxy acrylate (EA) resin, which originates from epoxides, has long been served as a photocurable coating and adhesive material owing to its double bonds. Specifically, alkaline-developable EA resins can be used as a ...Epoxy acrylate (EA) resin, which originates from epoxides, has long been served as a photocurable coating and adhesive material owing to its double bonds. Specifically, alkaline-developable EA resins can be used as a binder polymer in negative-tone photoresists. In this work, we synthesized a series of acidic polyester-type epoxy methacrylate resins, characterized the intermediates and products, and tested their performance as a binder polymer for the photolithographic micro-patterning of the pixel-defining layer on organic light-emitting diodes in comparison to a widely used commercial binder polymer. Copolymer-type binder polymer BP-2-2 was produced excellent patterning with no residue due to its high compatibility with the black mill base.展开更多
Extreme ultraviolet lithography(EUVL)and electron beam lithography(EBL)are considered to be crucial lithography techniques utilized in the fabrication of nanoscale semiconductor devices.However,the industry currently ...Extreme ultraviolet lithography(EUVL)and electron beam lithography(EBL)are considered to be crucial lithography techniques utilized in the fabrication of nanoscale semiconductor devices.However,the industry currently faces a scarcity of EUV photoresists that meet the increasingly challenging standards in terms of resolution,sensitivity and roughness.Metal oxo nanoclusters have garnered significant interest in the field of EUV photoresist due to their relatively stronger absorption cross-section for extreme ultraviolet light and lower dimensions.In this study,we utilize a heterometallic nanocluster strategy by a combination of titanium and zirconium metals to investigate their solubility,assess the suitability of various developers,and evaluate their performance in electron-beam and EUVL,as well as study their etch resistance for pattern transfer.We demonstrate that R-4 is able to get a critical dimension(CD)of 25 nm at low doses under EBL,as well as 50 nm resolution at EUVL with a remarkable sensitivity of 19.7 mJ cm−2.This study offers an efficient heterometallic method for optimizing the lithographic performance of metal oxo nanocluster photoresists,which can benefit the development of commercially viable next-generation EUV photoresists.展开更多
A device was designed and assembled to analyze the outgassing of molecular glass(MG)photoresists under extreme ultraviolet(EUV)exposure.The outgassing of the photoresists with different components and different concen...A device was designed and assembled to analyze the outgassing of molecular glass(MG)photoresists under extreme ultraviolet(EUV)exposure.The outgassing of the photoresists with different components and different concentrations of tert-butoxycarbonyl(t-Boc),photo-generated acid(PAG),and acid quencher was systematically investigated.Based on experiments,some solutions for reducing the outgassing of MG photoresists were proposed.展开更多
Extreme ultraviolet(EUV)photoresists have become the core materials in lithography with nanometer-sized patterns and are actively explored on the path to realizing smaller critical dimensions.These photoresists can be...Extreme ultraviolet(EUV)photoresists have become the core materials in lithography with nanometer-sized patterns and are actively explored on the path to realizing smaller critical dimensions.These photoresists can be small molecule-,polymer-,or organic–inorganic hybrid-based,with the full molecular working mechanism under investigation.For the rational design of EUV photoresists,theoretical guidance using tools like first-principle calculations and multi-scale simulations can be of great help.Considering the extremely high standard of accuracy in EUV lithography,it is critical to ensure the adoption of the appropriate methodologies in the theoretical evaluation of EUV photoresists.However,it is known that density func-tionals and semi-empirical methods differ in accuracy and efficiency,without a universal rule across materials.This poses a challenge in developing a reliable theoretical framework for calculating EUV photoresists.Here,we present a benchmark investigation of density functionals and semi-empirical methods on the three main types of EUV photoresists,focusing on the ionization potential,a key parameter in their microscopic molecular reactions.The vertical detachment energies(VDE)and adiabatic detachment energies(ADE)were calculated using 12 functionals,including pure functionals,hybrid functionals,Minnesota functionals,and the recently developed optimally tuned range-separated(OTRS)functionals.Several efficient semi-empirical methods were also chosen,including AM1,PM6,PM7,and GFN1-xTB in the extended tight-binding theo-retical framework.These results guide the accurate and efficient calculation of EUV photoresists and are valuable for the development of multi-scale lithography protocols.展开更多
In photolithography,shortening the exposure wavelength from ultraviolet to extreme ultraviolet(EUV,13.5 nm)and soft X-ray region in terms of beyond EUV(BEUV,6.X nm)and water window X-ray(WWX,2.2–4.4 nm)is expected to...In photolithography,shortening the exposure wavelength from ultraviolet to extreme ultraviolet(EUV,13.5 nm)and soft X-ray region in terms of beyond EUV(BEUV,6.X nm)and water window X-ray(WWX,2.2–4.4 nm)is expected to further miniaturize the technology node down to sub-5 nm level.However,the absorption ability of molecules in these ranges,especially WWX region,is unknown,which should be very important for the utilization of energy.Herein,the molar absorption cross sections of different elements at 2.4 nm of WWX were firstly calculated and compared with the wavelengths of 13.5 nm and 6.7 nm.Based on the absorption cross sections in these ranges and density estimation results from the density-functional theory calculation,the linear absorption coefficients of typical resist materials,including metal-oxy clusters,organic small molecules,polymers,and photoacid generators(PAGs),are evaluated.The analysis suggests that the Zn cluster has higher absorption in BEUV,whereas the Sn cluster has higher absorption in WWX.Doping PAGs with high EUV absorption atoms improves chemically amplified photoresist(CAR)polymer absorption performance.However,for WWX,it is necessary to introduce an absorption layer containing high WWX absorption elements such as Zr,Sn,and Hf to increase the WWX absorption.展开更多
Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polym...Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polymers possess low intrinsic viscosities and high thermal stabilities, losing little of their weights when heated to 〉 400℃. Upon pyrolysis at 〉 800℃, the polymers graphitize with high char yields （up to 86%）. Hyperbranched polyarylenes efficiently emit deep-blue to blue-green lights with fluorescence quantum yields up to 98% and strongly attenuate intense laser pulses with optical power-limiting performances superior to that of C60, a well-known optical limiter. Poly（alkenephenylenes）, poly（aroylarylenes） and polyynes are readily cross-linkable by UV irradiation, serving as excellent photoresist materials for the generation of patterns with nanometer resolution. Thin films of hyperbranched polyynes exhibit very high refractive indexes （n up to 1.86）. The internal and terminal acetylene moieties of the polyynes readily form complexes with cobalt carbonyls, which can be transformed into soft ferromagnetic ceramics with high magnetic susceptibilities （Ms up to ca. 118 emu/g） and near-zero magnetic losses.展开更多
The matrix polymer PTBCHNB bearing o-nitrobenzyl group was successfully synthesized by copolymerization of tertiary-butyl methacrylate(TBMA), cyclohexyl methacrylate(CHMA) and o-nitrobenzyl methacrylate(NBMA) via reve...The matrix polymer PTBCHNB bearing o-nitrobenzyl group was successfully synthesized by copolymerization of tertiary-butyl methacrylate(TBMA), cyclohexyl methacrylate(CHMA) and o-nitrobenzyl methacrylate(NBMA) via reversible addition fragmentation chain transfer(RAFT) polymerization method. PTBCHNB was characterized by FTIR, 1HNMR, GPC and DSC. After UV irradiation, the o-nitrobenzyl groups of PTBCHNB were photocleaved and the resulting carboxyl groups were highly alkali soluble, and PTBCHNB was converted to PCHIBMA bearing carboxyl groups. So, the matrix polymer could be etched by mild alkali solution with no requirements of photoacid generators and other diverse additives. The photocleavable behaviors of PTBCHNB were determined by FTIR, 1H NMR and TGA analysis. The resist formulated with PTBCHNB and cast in THF solution showed square pattern of 10 μm×10 μm using a mercury-xenon lamp in a contact printing mode and tetramethyl-ammonium hydroxide aqueous solution as a developer.展开更多
A novel biopolymer, deoxyribonucleic acid-hexadecyltrimethylammonium chloride (DNA-HCTAC), is used as the core layer material in optical waveguide, and the cleanroom technology is successfully applied to fabricate the...A novel biopolymer, deoxyribonucleic acid-hexadecyltrimethylammonium chloride (DNA-HCTAC), is used as the core layer material in optical waveguide, and the cleanroom technology is successfully applied to fabricate the single-mode channel waveguides with low propagation loss. The prepared DNA-HCTAC material shows high optical quality at the optical telecommunication wavelengths, such as high transparency, relatively high refractive index and low birefringence. In the fabrication approach, polymethyl methacrylate (PMMA) is used as a barrier layer to protect the DNA-HCTAC material from the corrosive of photoresist developer, and the etching conditions are optimized to form the smooth wall and sharp cross-section of the waveguide. Lastly, the optical characteristics of DNA-HCTAC channel waveguides are measured. The results show that the DNA-HCTAC waveguide operates with single-mode propagation and has a low optical loss.展开更多
We report one thick layer of hard-baked photoresist mask.The laser array stripe pattern was defined by standard wet lithography.With this mask, a 10 W QCW(quasi-continuous wave) operation of a narrow proton implanted ...We report one thick layer of hard-baked photoresist mask.The laser array stripe pattern was defined by standard wet lithography.With this mask, a 10 W QCW(quasi-continuous wave) operation of a narrow proton implanted multiple stripe conventional single quantum well separate confinement heterostructure(SQW-SCH) GaAlAs diode laser array has been realized.These devices exhibit the lateral far-field radiation pattern of a phase-locked array of gain-guided semiconductor injection laser array.The twenty stripe laser array has a lateral far-field beam divergence full width at half maximum(FWHM) of less than 3°,and three twenty stripe laser array has a beam divergence in the plane of the junction of about 9°.展开更多
The application of surface textures has been employed to improve the tribological performance of various mechanical components. Various techniques have been used for the application of surface textures such as micro-d...The application of surface textures has been employed to improve the tribological performance of various mechanical components. Various techniques have been used for the application of surface textures such as micro-dimple arrays, but the fabrication of such arrays on cylindrical inner surfaces remains a challenge. In this study, a dry-film photoresist is used as a mask during through-mask electrochemical micromachining to successfully prepare micro-dimple arrays with dimples 94 lm in diameter and 22.7 lm deep on cylindrical inner surfaces, with a machining time of 9 s and an applied voltage of 8 V. The versatility of this method is demonstrated, as are its potential low cost and high efficiency. It is also shown that for a fixed dimple depth, a smaller dimple diameter can be obtained using a combination of lower current density and longer machining time in a passivating sodium nitrate electrolyte.展开更多
UV-curable hyperbranched polyurethane （UV-HBPU） containing carboxyl groups was synthesized from isophorone diisocyanate （IPDI）, diethanolamine （DEOA）, polyethylene glycol （PEG-400）, hydroxyethyl acrylate （HEA...UV-curable hyperbranched polyurethane （UV-HBPU） containing carboxyl groups was synthesized from isophorone diisocyanate （IPDI）, diethanolamine （DEOA）, polyethylene glycol （PEG-400）, hydroxyethyl acrylate （HEA）, and 2,2-his （hydroxymethyl） propionic acid （DMPA）. The UV-HBPU was used as a negative-type photoresist for a printed circuit board （PCB）. Fourier-transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （1HNMR） spectroscopy of UV-HBPUs indicated that the synthesis was successful. Differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA） showed that the thermal stability of the UV-HBPUs decreased as the HEA content increased. The polymer exhibited excellent photoresist properties, and the resolution of circuits based on this negative-type photoresist reached 10 μm.展开更多
In this paper,we report the study of the process of fabricating a multi-layermetal micro-structure using UV-LIGA overlay technology,includingmask fabrication,substrate treatment,and UV-LIGA overlay processes.To solve ...In this paper,we report the study of the process of fabricating a multi-layermetal micro-structure using UV-LIGA overlay technology,includingmask fabrication,substrate treatment,and UV-LIGA overlay processes.To solve the process problems in the masking procedure,the swelling problemof the first layer of SU-8 thick photoresist was studied experimentally.The 5μmline-width compensation and closed 20μmand 30μmisolation strips were designed and fabricated around the micro-structure pattern.The pore problemin the Ni micro-electroforming layer was analyzed and the electroforming parameters were improved.The pH value of the electroforming solution should be controlled between 3.8 and 4.4 and the current density should be below 3 A/dm^2.To solve the problems of high inner stress and incomplete development of the micro-cylinder hole array with a diameter of 30μm,the lithography process was optimized.The pre-baking temperature was increased via gradient heating and rose every 5℃ from 65℃ to 85℃ and then remained at 85℃ for 50 min–1 h.In addition,the full contact exposure was used.Finally,a multi-layer metal micro-structure with high precision and good quality of microelectroforming layer was fabricated using UV-LIGA overlay technology.展开更多
In this study,we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization.The results indicate that the mechani...In this study,we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization.The results indicate that the mechanical performance of the thiol-ene photoresin is highly depended on the exposure dose during the solidification process.With 350-fold exposure dose change,the stiffness of the thiol-ene photoresin reached more that 700-fold change compare to 14-fold of the acrylate photoresin.We developed a TPL photoresist based on our results and show the capability to fabricate microstrucutres with high resolution and variable mechanical performances using this method.展开更多
Ion＇s behavior plays an important role in plasma etching processes and is determined by the local electric potential in the etched trenches. In this study, with the trench powered by a radio frequency （rf） source, ...Ion＇s behavior plays an important role in plasma etching processes and is determined by the local electric potential in the etched trenches. In this study, with the trench powered by a radio frequency （rf） source, the Laplace equation is solved to obtain the electric potential. The ion trajectories and the ion energy distribution （IED） at the bottom of the trench are obtained self-consistently by tracking the ions in the trench. The results show that the aspect ratio of depth- to-width of the photoresist trench and the voltage amplitude of the rf source applied to the electrode are important parameters. The larger the aspect ratio and the smaller the amplitude are, the more ions hit the sidewalls, which results in a notching phenomenon. Meanwhile, there are a higher high-energy peak and a lower low-energy peak in the IED with the increase in aspect ratio.展开更多
Evaluating the comprehensive characteristics of extreme ultraviolet(EUV)photoresists is crucial for their application in EUV lithography,a key process in modern technology.This paper highlights the capabilities of the...Evaluating the comprehensive characteristics of extreme ultraviolet(EUV)photoresists is crucial for their application in EUV lithography,a key process in modern technology.This paper highlights the capabilities of the Shanghai Synchrotron Radiation Facility(SSRF)08U1B beamline in advancing this field.Specifically,it demonstrates how this beamline can create fringe patterns with a 15-nm half-pitch on a resist using synchrotron-based EUV lithography.This achievement is vital for evaluating EUV photoresists at the advanced 5-nm node.We provide a detailed introduction to the methods and experimental setup used at the SSRF 08U1B beamline to assess an EUV photoresist.A significant part of this research involved the fabrication of high-resolution hydrogen silsesquioxane mask gratings.These gratings,with an aspect ratio of approximately 3,were created using electron beam lithography on an innovative mask framework.This framework was crucial in eliminating the impact of zeroth-order light on interference patterns.The proposed framework propose offers a new approach to mask fabrication,particularly beneficial for achromatic Talbot lithography and multicoherent-beam interference applications.展开更多
Invar alloy consisting of 64% iron and 36% nickel has been widely used for the production of shadow masks for organic light emitting diodes（OLEDs） because of its low thermal expansion coefficient（1.86 × 10^-6c...Invar alloy consisting of 64% iron and 36% nickel has been widely used for the production of shadow masks for organic light emitting diodes（OLEDs） because of its low thermal expansion coefficient（1.86 × 10^-6cm/°C）.To fabricate micro-hole arrays on 30 lm invar alloy film,through-mask electrochemical micromachining（TMEMM） was developed and combined with a portion of the photolithography etching process.For precise hole shapes,patterned photoresist（PR） film was applied as an insulating mask.To investigate the relationship between the current density and the material removal rate,the principle of the electrochemical machining was studied with a focus on the equation.The finite element method（FEM） was used to verify the influence of each parameter on the current density on the invar alloy film surface.The parameters considered were the thickness of the PR mask,inter-electrode gap（IEG）,and electrolyte concentration.Design of experiments（DOE） was used to figure out the contribution of each parameter.A simulation was conducted with varying parameters to figure out their relationships with the current density.Optimization was conducted to select the suitable conditions.An experiment was carried out to verify the simulation results.It was possible to fabricate micro-hole arrays on invar alloy film using TMEMM,which is a promising method that can be applied to fabrications of OLEDs shadow masks.展开更多
Skin aging is a process most often attributed to UV<span><span><span style="font-family:" minion="" pro="" capt","serif";"=""><span styl...Skin aging is a process most often attributed to UV<span><span><span style="font-family:" minion="" pro="" capt","serif";"=""><span style="font-family:Verdana;"> </span></span></span></span><span><span><span style="font-family:" minion="" pro="" capt","serif";"=""><span></span></span></span></span><span><span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">[1]</span></span></span><span><span><span style="font-family:" color:#943634;"=""></span></span></span><span><span></span></span><span></span><span><span><span></span></span></span><span><span></span></span><span></span><span><span></span></span><span><span><span style="font-family:" color:red;"=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">and</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> also to the use of creams and other cosmetic products low in antioxidant compounds </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">[2]</span></span></span><span><span><span style="font-family:;" "=""></span></span></span><span><span></span></span><span></span><span><span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. Photochemically stable pepo Cucurbita oil can be used as an exogenous cosmetic supplement due to its high antioxidant content. Incorporated in an agar, media containing a synthetic melanin solution with added pumpkin oil are subjected to UV light, the aging thus modeled is followed by the measurement of photoresistance values correlated with chemical and spectrophotometric analyses. This study confirms that pumpkin oil is highly effective in protecting the skin, especially the most sensitive skins such as babies’ skin </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">[3]</span></span></span><span><span><span style="font-family:;" "=""></span></span></span><span><span></span></span><span></span><span><span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> by reinforcing the action of melanin </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">and</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> also that of albinos without melanin. Indeed its SPF (<b>Significant Sun Protection Factor</b>) index estimated during this work is very consistent,</span><i><span style="font-family:Verdana;"> i.e.</span></i><span style="font-family:Verdana;"> more than 22% of UVB (<b>280</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:Verdana;">315 nm</b>) radiations are suppressed.展开更多
Photolithography has been a major enabler for the continuous shrink of the semiconductor manufacturing design rules.Throughout the years of the development of the photolithography,many new technologies have been inven...Photolithography has been a major enabler for the continuous shrink of the semiconductor manufacturing design rules.Throughout the years of the development of the photolithography,many new technologies have been invented and successfully implemented,such as image projection lithography,chemically amplified photoresist,phase shifting mask,optical proximity modeling and correction,etc.From 0.25μm technology to the current 7 nm technology,the linewidth has been shrunk from 250 nm to about 20 nm,or 12.5 times.Although imaging resolution is proportional to the illumination wavelength,with the new technologies,the wavelength has only been shrunk from 248 nm to 134.7 nm(193 nm immersion in water),less than 2 times.Would it mean that the imaging performance has been continuously declining?Or we have yet fully utilized the potential of the photolithography technology?In this paper,we will present a study on the key parameters and process window performance of the image projection photolithography from 0.25μm node to the current 7 nm node.展开更多
基金This work is financially supported by the National Natural Science Foundation of China.
文摘The copolymers of chloroethyl methacrylate (CMA), glycidyl methacrylate (GMA), and methyl methacrylate (MMA) were synthesized in benzene solution. Their breadths of the molecular weight distributions are 2.1 and 2.3, respectively. The thermal stability of P(GMA-CMA) is superior to that of P(CMA-MMA). The resolutions of P(CMA-MMA) and P(GMA-CMA) photoresists were found to be 0.1-0.16 mu m and 0.17-0.2 mu m, respectively. (Author abstract) 9 Refs.
基金Financial support from the National Natural Science Foundation of China(22090012,U20A20144,21873106,22073108 and 21903085)the Ministry of Science and Technology of China Major Project(2018ZX02102005,2011ZX02701)is gratefully acknowledged.
文摘Photoresists are radiation-sensitive materials used for forming patterns to build up IC devices.To date,most photoresists have been based on organic polymers,which have been dominating the semiconductor industries over the past few decades.It is obvious that extreme ultraviolet(EUV)lithography has become the next-generation lithography technology.The development of comprehensive performance EUV resist is one of the most critical issues.However,organic polymeric photoresists are difficult to meet the harsh requirements of EUV lithography.Pure inorganic photoresists such as metal salts,hydrogen silsesquioxane(HSQ)are expected for EUV lithography due to their high resistance and high resolution.But the low sensitivity makes them not suitable for high volume manufacturing(HVM).Organic-inorganic hybrid photoresists,containing both organic and inorganic components,are regarded as one of the most promising EUV resists.They combine both merits of organic and inorganic materials and have significant advantages in machinability,etching resistance,EUV absorption,and chemical/thermal stability.Organic-inorganic hybrid photoresists are considered as ideal materials for realizing industrialgrade patterns below 10 nm.This review mainly focuses on the development of organic-inorganic hybrid photoresists over the past decade.
文摘Epoxy acrylate (EA) resin, which originates from epoxides, has long been served as a photocurable coating and adhesive material owing to its double bonds. Specifically, alkaline-developable EA resins can be used as a binder polymer in negative-tone photoresists. In this work, we synthesized a series of acidic polyester-type epoxy methacrylate resins, characterized the intermediates and products, and tested their performance as a binder polymer for the photolithographic micro-patterning of the pixel-defining layer on organic light-emitting diodes in comparison to a widely used commercial binder polymer. Copolymer-type binder polymer BP-2-2 was produced excellent patterning with no residue due to its high compatibility with the black mill base.
基金supported by the National Natural Science Foundation of China(22271284 and 91961108)“the Fundamental Research Funds for the Central Universities”,Nankai University(075-63233091)。
文摘Extreme ultraviolet lithography(EUVL)and electron beam lithography(EBL)are considered to be crucial lithography techniques utilized in the fabrication of nanoscale semiconductor devices.However,the industry currently faces a scarcity of EUV photoresists that meet the increasingly challenging standards in terms of resolution,sensitivity and roughness.Metal oxo nanoclusters have garnered significant interest in the field of EUV photoresist due to their relatively stronger absorption cross-section for extreme ultraviolet light and lower dimensions.In this study,we utilize a heterometallic nanocluster strategy by a combination of titanium and zirconium metals to investigate their solubility,assess the suitability of various developers,and evaluate their performance in electron-beam and EUVL,as well as study their etch resistance for pattern transfer.We demonstrate that R-4 is able to get a critical dimension(CD)of 25 nm at low doses under EBL,as well as 50 nm resolution at EUVL with a remarkable sensitivity of 19.7 mJ cm−2.This study offers an efficient heterometallic method for optimizing the lithographic performance of metal oxo nanocluster photoresists,which can benefit the development of commercially viable next-generation EUV photoresists.
基金financially supported by the National Natural Science Foundation of China(21373240,91123033,21233011)the National Science and Technology Major Project of China(2011ZX02701)
文摘A device was designed and assembled to analyze the outgassing of molecular glass(MG)photoresists under extreme ultraviolet(EUV)exposure.The outgassing of the photoresists with different components and different concentrations of tert-butoxycarbonyl(t-Boc),photo-generated acid(PAG),and acid quencher was systematically investigated.Based on experiments,some solutions for reducing the outgassing of MG photoresists were proposed.
基金supported by the National Natural Science Foundation of China(grant number 22090013)the Shanghai Committee of Science and Technology(grant numbers:21QA1402900 and YDZX20213100002672).
文摘Extreme ultraviolet(EUV)photoresists have become the core materials in lithography with nanometer-sized patterns and are actively explored on the path to realizing smaller critical dimensions.These photoresists can be small molecule-,polymer-,or organic–inorganic hybrid-based,with the full molecular working mechanism under investigation.For the rational design of EUV photoresists,theoretical guidance using tools like first-principle calculations and multi-scale simulations can be of great help.Considering the extremely high standard of accuracy in EUV lithography,it is critical to ensure the adoption of the appropriate methodologies in the theoretical evaluation of EUV photoresists.However,it is known that density func-tionals and semi-empirical methods differ in accuracy and efficiency,without a universal rule across materials.This poses a challenge in developing a reliable theoretical framework for calculating EUV photoresists.Here,we present a benchmark investigation of density functionals and semi-empirical methods on the three main types of EUV photoresists,focusing on the ionization potential,a key parameter in their microscopic molecular reactions.The vertical detachment energies(VDE)and adiabatic detachment energies(ADE)were calculated using 12 functionals,including pure functionals,hybrid functionals,Minnesota functionals,and the recently developed optimally tuned range-separated(OTRS)functionals.Several efficient semi-empirical methods were also chosen,including AM1,PM6,PM7,and GFN1-xTB in the extended tight-binding theo-retical framework.These results guide the accurate and efficient calculation of EUV photoresists and are valuable for the development of multi-scale lithography protocols.
基金supported by the National Natural Science Foundation of China(22090011,22378052)the Fundamental Research Funds for China Central Universities(DUT22LAB608 and DUT20RC(3)030)+1 种基金Liaoning Binhai Laboratory(LBLB-2023-03)Key R&D Program of Shandong Province(2021CXGC010308).
文摘In photolithography,shortening the exposure wavelength from ultraviolet to extreme ultraviolet(EUV,13.5 nm)and soft X-ray region in terms of beyond EUV(BEUV,6.X nm)and water window X-ray(WWX,2.2–4.4 nm)is expected to further miniaturize the technology node down to sub-5 nm level.However,the absorption ability of molecules in these ranges,especially WWX region,is unknown,which should be very important for the utilization of energy.Herein,the molar absorption cross sections of different elements at 2.4 nm of WWX were firstly calculated and compared with the wavelengths of 13.5 nm and 6.7 nm.Based on the absorption cross sections in these ranges and density estimation results from the density-functional theory calculation,the linear absorption coefficients of typical resist materials,including metal-oxy clusters,organic small molecules,polymers,and photoacid generators(PAGs),are evaluated.The analysis suggests that the Zn cluster has higher absorption in BEUV,whereas the Sn cluster has higher absorption in WWX.Doping PAGs with high EUV absorption atoms improves chemically amplified photoresist(CAR)polymer absorption performance.However,for WWX,it is necessary to introduce an absorption layer containing high WWX absorption elements such as Zr,Sn,and Hf to increase the WWX absorption.
基金This work was partially supported by the Hong Kong Research Grants Council,the University Grants Committee of Hong Kong,and the National Natural Science Foundation of China.
文摘Polycyclotrimerization and polycoupling of acetylenic monomers respectively furnish hyperbranched polyarylenes and polyynes with high molecular weights （up to 1 × 10^6） in high yields （up to 99.9%）. The polymers possess low intrinsic viscosities and high thermal stabilities, losing little of their weights when heated to 〉 400℃. Upon pyrolysis at 〉 800℃, the polymers graphitize with high char yields （up to 86%）. Hyperbranched polyarylenes efficiently emit deep-blue to blue-green lights with fluorescence quantum yields up to 98% and strongly attenuate intense laser pulses with optical power-limiting performances superior to that of C60, a well-known optical limiter. Poly（alkenephenylenes）, poly（aroylarylenes） and polyynes are readily cross-linkable by UV irradiation, serving as excellent photoresist materials for the generation of patterns with nanometer resolution. Thin films of hyperbranched polyynes exhibit very high refractive indexes （n up to 1.86）. The internal and terminal acetylene moieties of the polyynes readily form complexes with cobalt carbonyls, which can be transformed into soft ferromagnetic ceramics with high magnetic susceptibilities （Ms up to ca. 118 emu/g） and near-zero magnetic losses.
基金Project(2008AA03323) supported by the High-Tech Research and Development of ChinaProject(21374016) supported by the National Natural Science Foundation of ChinaProject(BY201153) supported by Production,Forward-Looking Joint Research Project of Jiangsu Province,China
文摘The matrix polymer PTBCHNB bearing o-nitrobenzyl group was successfully synthesized by copolymerization of tertiary-butyl methacrylate(TBMA), cyclohexyl methacrylate(CHMA) and o-nitrobenzyl methacrylate(NBMA) via reversible addition fragmentation chain transfer(RAFT) polymerization method. PTBCHNB was characterized by FTIR, 1HNMR, GPC and DSC. After UV irradiation, the o-nitrobenzyl groups of PTBCHNB were photocleaved and the resulting carboxyl groups were highly alkali soluble, and PTBCHNB was converted to PCHIBMA bearing carboxyl groups. So, the matrix polymer could be etched by mild alkali solution with no requirements of photoacid generators and other diverse additives. The photocleavable behaviors of PTBCHNB were determined by FTIR, 1H NMR and TGA analysis. The resist formulated with PTBCHNB and cast in THF solution showed square pattern of 10 μm×10 μm using a mercury-xenon lamp in a contact printing mode and tetramethyl-ammonium hydroxide aqueous solution as a developer.
基金supported by the International Collaboration Project of Ningbo (No.2010D10018)the Research and Innovation Project of Zhejiang Province (No.2011R405050)the Research Fund of Graduate of Ningbo University (No.G11JA001)
文摘A novel biopolymer, deoxyribonucleic acid-hexadecyltrimethylammonium chloride (DNA-HCTAC), is used as the core layer material in optical waveguide, and the cleanroom technology is successfully applied to fabricate the single-mode channel waveguides with low propagation loss. The prepared DNA-HCTAC material shows high optical quality at the optical telecommunication wavelengths, such as high transparency, relatively high refractive index and low birefringence. In the fabrication approach, polymethyl methacrylate (PMMA) is used as a barrier layer to protect the DNA-HCTAC material from the corrosive of photoresist developer, and the etching conditions are optimized to form the smooth wall and sharp cross-section of the waveguide. Lastly, the optical characteristics of DNA-HCTAC channel waveguides are measured. The results show that the DNA-HCTAC waveguide operates with single-mode propagation and has a low optical loss.
文摘We report one thick layer of hard-baked photoresist mask.The laser array stripe pattern was defined by standard wet lithography.With this mask, a 10 W QCW(quasi-continuous wave) operation of a narrow proton implanted multiple stripe conventional single quantum well separate confinement heterostructure(SQW-SCH) GaAlAs diode laser array has been realized.These devices exhibit the lateral far-field radiation pattern of a phase-locked array of gain-guided semiconductor injection laser array.The twenty stripe laser array has a lateral far-field beam divergence full width at half maximum(FWHM) of less than 3°,and three twenty stripe laser array has a beam divergence in the plane of the junction of about 9°.
基金supported by the Joint Funds of the National Natural Science Foundation of China and Guangdong Province(No.U1134003)
文摘The application of surface textures has been employed to improve the tribological performance of various mechanical components. Various techniques have been used for the application of surface textures such as micro-dimple arrays, but the fabrication of such arrays on cylindrical inner surfaces remains a challenge. In this study, a dry-film photoresist is used as a mask during through-mask electrochemical micromachining to successfully prepare micro-dimple arrays with dimples 94 lm in diameter and 22.7 lm deep on cylindrical inner surfaces, with a machining time of 9 s and an applied voltage of 8 V. The versatility of this method is demonstrated, as are its potential low cost and high efficiency. It is also shown that for a fixed dimple depth, a smaller dimple diameter can be obtained using a combination of lower current density and longer machining time in a passivating sodium nitrate electrolyte.
基金Funded by the National Natural Science Foundation of China(Nos.51203063,51103064)
文摘UV-curable hyperbranched polyurethane （UV-HBPU） containing carboxyl groups was synthesized from isophorone diisocyanate （IPDI）, diethanolamine （DEOA）, polyethylene glycol （PEG-400）, hydroxyethyl acrylate （HEA）, and 2,2-his （hydroxymethyl） propionic acid （DMPA）. The UV-HBPU was used as a negative-type photoresist for a printed circuit board （PCB）. Fourier-transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （1HNMR） spectroscopy of UV-HBPUs indicated that the synthesis was successful. Differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA） showed that the thermal stability of the UV-HBPUs decreased as the HEA content increased. The polymer exhibited excellent photoresist properties, and the resolution of circuits based on this negative-type photoresist reached 10 μm.
文摘In this paper,we report the study of the process of fabricating a multi-layermetal micro-structure using UV-LIGA overlay technology,includingmask fabrication,substrate treatment,and UV-LIGA overlay processes.To solve the process problems in the masking procedure,the swelling problemof the first layer of SU-8 thick photoresist was studied experimentally.The 5μmline-width compensation and closed 20μmand 30μmisolation strips were designed and fabricated around the micro-structure pattern.The pore problemin the Ni micro-electroforming layer was analyzed and the electroforming parameters were improved.The pH value of the electroforming solution should be controlled between 3.8 and 4.4 and the current density should be below 3 A/dm^2.To solve the problems of high inner stress and incomplete development of the micro-cylinder hole array with a diameter of 30μm,the lithography process was optimized.The pre-baking temperature was increased via gradient heating and rose every 5℃ from 65℃ to 85℃ and then remained at 85℃ for 50 min–1 h.In addition,the full contact exposure was used.Finally,a multi-layer metal micro-structure with high precision and good quality of microelectroforming layer was fabricated using UV-LIGA overlay technology.
基金the National Natural Science Foundation of China(Nos.22002015 and 52033002)the Fundamental Research Funding from Jiangsu Province(No.BK20211560)the Fundamental Research Funds for the Central Universities(No.2242018R20011).
文摘In this study,we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization.The results indicate that the mechanical performance of the thiol-ene photoresin is highly depended on the exposure dose during the solidification process.With 350-fold exposure dose change,the stiffness of the thiol-ene photoresin reached more that 700-fold change compare to 14-fold of the acrylate photoresin.We developed a TPL photoresist based on our results and show the capability to fabricate microstrucutres with high resolution and variable mechanical performances using this method.
基金supported by National Natural Science Foundation of China (Nos.11075029, 10975030)the Important National Science and Technology Specific Project of China (No.2011ZX02403-001)
文摘Ion＇s behavior plays an important role in plasma etching processes and is determined by the local electric potential in the etched trenches. In this study, with the trench powered by a radio frequency （rf） source, the Laplace equation is solved to obtain the electric potential. The ion trajectories and the ion energy distribution （IED） at the bottom of the trench are obtained self-consistently by tracking the ions in the trench. The results show that the aspect ratio of depth- to-width of the photoresist trench and the voltage amplitude of the rf source applied to the electrode are important parameters. The larger the aspect ratio and the smaller the amplitude are, the more ions hit the sidewalls, which results in a notching phenomenon. Meanwhile, there are a higher high-energy peak and a lower low-energy peak in the IED with the increase in aspect ratio.
基金supported by the National Key Research and Development Program of China(Nos.2021YFA1601003,2017YFA0206002,2017YFA0403400)the National Natural Science Foundation of China(No.11775291)。
文摘Evaluating the comprehensive characteristics of extreme ultraviolet(EUV)photoresists is crucial for their application in EUV lithography,a key process in modern technology.This paper highlights the capabilities of the Shanghai Synchrotron Radiation Facility(SSRF)08U1B beamline in advancing this field.Specifically,it demonstrates how this beamline can create fringe patterns with a 15-nm half-pitch on a resist using synchrotron-based EUV lithography.This achievement is vital for evaluating EUV photoresists at the advanced 5-nm node.We provide a detailed introduction to the methods and experimental setup used at the SSRF 08U1B beamline to assess an EUV photoresist.A significant part of this research involved the fabrication of high-resolution hydrogen silsesquioxane mask gratings.These gratings,with an aspect ratio of approximately 3,were created using electron beam lithography on an innovative mask framework.This framework was crucial in eliminating the impact of zeroth-order light on interference patterns.The proposed framework propose offers a new approach to mask fabrication,particularly beneficial for achromatic Talbot lithography and multicoherent-beam interference applications.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.2015R1A2A1A15054116)
文摘Invar alloy consisting of 64% iron and 36% nickel has been widely used for the production of shadow masks for organic light emitting diodes（OLEDs） because of its low thermal expansion coefficient（1.86 × 10^-6cm/°C）.To fabricate micro-hole arrays on 30 lm invar alloy film,through-mask electrochemical micromachining（TMEMM） was developed and combined with a portion of the photolithography etching process.For precise hole shapes,patterned photoresist（PR） film was applied as an insulating mask.To investigate the relationship between the current density and the material removal rate,the principle of the electrochemical machining was studied with a focus on the equation.The finite element method（FEM） was used to verify the influence of each parameter on the current density on the invar alloy film surface.The parameters considered were the thickness of the PR mask,inter-electrode gap（IEG）,and electrolyte concentration.Design of experiments（DOE） was used to figure out the contribution of each parameter.A simulation was conducted with varying parameters to figure out their relationships with the current density.Optimization was conducted to select the suitable conditions.An experiment was carried out to verify the simulation results.It was possible to fabricate micro-hole arrays on invar alloy film using TMEMM,which is a promising method that can be applied to fabrications of OLEDs shadow masks.
文摘Skin aging is a process most often attributed to UV<span><span><span style="font-family:" minion="" pro="" capt","serif";"=""><span style="font-family:Verdana;"> </span></span></span></span><span><span><span style="font-family:" minion="" pro="" capt","serif";"=""><span></span></span></span></span><span><span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">[1]</span></span></span><span><span><span style="font-family:" color:#943634;"=""></span></span></span><span><span></span></span><span></span><span><span><span></span></span></span><span><span></span></span><span></span><span><span></span></span><span><span><span style="font-family:" color:red;"=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">and</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> also to the use of creams and other cosmetic products low in antioxidant compounds </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">[2]</span></span></span><span><span><span style="font-family:;" "=""></span></span></span><span><span></span></span><span></span><span><span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. Photochemically stable pepo Cucurbita oil can be used as an exogenous cosmetic supplement due to its high antioxidant content. Incorporated in an agar, media containing a synthetic melanin solution with added pumpkin oil are subjected to UV light, the aging thus modeled is followed by the measurement of photoresistance values correlated with chemical and spectrophotometric analyses. This study confirms that pumpkin oil is highly effective in protecting the skin, especially the most sensitive skins such as babies’ skin </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">[3]</span></span></span><span><span><span style="font-family:;" "=""></span></span></span><span><span></span></span><span></span><span><span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> by reinforcing the action of melanin </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">and</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> also that of albinos without melanin. Indeed its SPF (<b>Significant Sun Protection Factor</b>) index estimated during this work is very consistent,</span><i><span style="font-family:Verdana;"> i.e.</span></i><span style="font-family:Verdana;"> more than 22% of UVB (<b>280</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:Verdana;">315 nm</b>) radiations are suppressed.
文摘Photolithography has been a major enabler for the continuous shrink of the semiconductor manufacturing design rules.Throughout the years of the development of the photolithography,many new technologies have been invented and successfully implemented,such as image projection lithography,chemically amplified photoresist,phase shifting mask,optical proximity modeling and correction,etc.From 0.25μm technology to the current 7 nm technology,the linewidth has been shrunk from 250 nm to about 20 nm,or 12.5 times.Although imaging resolution is proportional to the illumination wavelength,with the new technologies,the wavelength has only been shrunk from 248 nm to 134.7 nm(193 nm immersion in water),less than 2 times.Would it mean that the imaging performance has been continuously declining?Or we have yet fully utilized the potential of the photolithography technology?In this paper,we will present a study on the key parameters and process window performance of the image projection photolithography from 0.25μm node to the current 7 nm node.
