A surface plasmon interference lithography assisted by a Fabry-Perot （F-P） cavity composed of subwavelength metal gratings and a thin metal fihn is proposed to fabricate high-quality nanopatterns. The calculated res...A surface plasmon interference lithography assisted by a Fabry-Perot （F-P） cavity composed of subwavelength metal gratings and a thin metal fihn is proposed to fabricate high-quality nanopatterns. The calculated results indicate that uniform straight interference fringes with high contrast and high electric-field intensity are formed in the resist under the F-P cavity. The analyses of spatial frequency spectra illuminate the physical mechanism of the formation for the interference fringes. The influence of the F-P cavity spacing is discussed in detail. Moreover, the error analyses reveal that all parameters except the metal grating period in this scheme can bear large tolerances for the device fabrication.展开更多
The silver（Ag）/photoresist（PR）/Ag structure, widely used in plasmonic photolithography, is fabricated on silicon substrate. The surface roughness of the top Ag film is measured and analyzed systematically. In part...The silver（Ag）/photoresist（PR）/Ag structure, widely used in plasmonic photolithography, is fabricated on silicon substrate. The surface roughness of the top Ag film is measured and analyzed systematically. In particular, combined with template stripping technology, the lower side of the top Ag film is imaged by an atomic force microscope. The topographies show that the lower side surface is rougher than the initial surface of the subjacent PR film, which is mainly attributable to the deformation caused by particle collisions during the deposition of the Ag film. Additionally, further measurements show that the Ag film deposited on the PR exhibits a flatter upper side morphology than that directly deposited on the silicon substrate. This is explained by the different growth modes of Ag films on different substrates. This work will be beneficial to morphology analysis and performance evaluation for the films in optical and plasmonic devices.展开更多
Although grating fabrication technologies on solid materials are well developed,grating fabrication on free standing films is rather more difficult.We propose a new film grating fabrication method based on UV-nanoimpr...Although grating fabrication technologies on solid materials are well developed,grating fabrication on free standing films is rather more difficult.We propose a new film grating fabrication method based on UV-nanoimprint lithography.This method combines the grating fabrication technique using nanoimprint lithography with thin film preparation technology.It involves the fabrication of a PMMA grating by UV-nanoimprint lithography,followed by the preparation of a thin metal film on the PMMA grating and the patterning of the tensile film specimen through photolithography.After dissolving the PMMA layer,the tensile film specimen becomes a free standing structure.To identify the quality of the thin film specimen as well as the grating,the specimen is loaded with uniaxial tensile stress.The Moirémethod is adopted to measure the full-field deformation and the mechanical parameters of the film specimen.The successful results verify the potential of this method in grating fabrication on other film-like specimens.展开更多
Superconducting nanowire single photon detector （SNSPD）, as a new type of superconducting single photon detector （SPD）, has a broad application prospect in quantum communication and other fields. In order to prepa...Superconducting nanowire single photon detector （SNSPD）, as a new type of superconducting single photon detector （SPD）, has a broad application prospect in quantum communication and other fields. In order to prepare SNSPD with high performance, it is necessary to fabricate a large area of uniform meander nanowires, which is the core of the SNSPD. In this paper, we demonstrate a process of patterning ultra-thin NbN films into meander-type nanowires by using the nano- imprint technology. In this process, a combination of hot embossing nano-imprint lithography （HE-NIL） and ultraviolet nano-imprint lithography （UV-NIL） is used to transfer the meander nanowire structure from the NIL Si hard mold to the NbN film. We have successfully obtained a NbN nanowire device with uniform line width. The critical temperature （Tc） of the superconducting NbN meander nanowires is about 5 K and the critical current （lc） is about 3.5 μA at 2.5 K.展开更多
Ultra-thin (20-100nm) polymethylmethacrylate(PMMA) films prepared by Langmuir-Blodgett techniques have been explored as high resolution electron beam resists. A Hitachi S-450 Scanning Electron Microscope (SEM) has bee...Ultra-thin (20-100nm) polymethylmethacrylate(PMMA) films prepared by Langmuir-Blodgett techniques have been explored as high resolution electron beam resists. A Hitachi S-450 Scanning Electron Microscope (SEM) has been refitted for a high resolution electron beam exposure system. The lithographic properties and exposure conditions of LB PMMA films were investigated. 0.15μm lines-and-spaces patterns were achieved by using the SEM as the exposure tool. The results demonstrate that the etch resistance of such films is sufficiently good to allow patterning of a 20 nm aluminum film suitable for mask fabrication.展开更多
基金Supported by the Natural Science Foundation of Hebei Province under Grant Nos A2013402069 and A2013402081
文摘A surface plasmon interference lithography assisted by a Fabry-Perot （F-P） cavity composed of subwavelength metal gratings and a thin metal fihn is proposed to fabricate high-quality nanopatterns. The calculated results indicate that uniform straight interference fringes with high contrast and high electric-field intensity are formed in the resist under the F-P cavity. The analyses of spatial frequency spectra illuminate the physical mechanism of the formation for the interference fringes. The influence of the F-P cavity spacing is discussed in detail. Moreover, the error analyses reveal that all parameters except the metal grating period in this scheme can bear large tolerances for the device fabrication.
基金supported by the National Basic Research Program of China(Grant No.2013CBA01702)the National Natural Science Foundation of China(Grant No.11275045)
文摘The silver（Ag）/photoresist（PR）/Ag structure, widely used in plasmonic photolithography, is fabricated on silicon substrate. The surface roughness of the top Ag film is measured and analyzed systematically. In particular, combined with template stripping technology, the lower side of the top Ag film is imaged by an atomic force microscope. The topographies show that the lower side surface is rougher than the initial surface of the subjacent PR film, which is mainly attributable to the deformation caused by particle collisions during the deposition of the Ag film. Additionally, further measurements show that the Ag film deposited on the PR exhibits a flatter upper side morphology than that directly deposited on the silicon substrate. This is explained by the different growth modes of Ag films on different substrates. This work will be beneficial to morphology analysis and performance evaluation for the films in optical and plasmonic devices.
基金Supported by the National Basic Research Program of China under Grant Nos 2010CB631005 and 2011CB606105the National Natural Science Foundation of China under Grant Nos 11172151 and 90916010the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No 20090002110048.
文摘Although grating fabrication technologies on solid materials are well developed,grating fabrication on free standing films is rather more difficult.We propose a new film grating fabrication method based on UV-nanoimprint lithography.This method combines the grating fabrication technique using nanoimprint lithography with thin film preparation technology.It involves the fabrication of a PMMA grating by UV-nanoimprint lithography,followed by the preparation of a thin metal film on the PMMA grating and the patterning of the tensile film specimen through photolithography.After dissolving the PMMA layer,the tensile film specimen becomes a free standing structure.To identify the quality of the thin film specimen as well as the grating,the specimen is loaded with uniaxial tensile stress.The Moirémethod is adopted to measure the full-field deformation and the mechanical parameters of the film specimen.The successful results verify the potential of this method in grating fabrication on other film-like specimens.
基金supported by the National Basic Research Program of China(Grant Nos.2011CBA00106 and 2009CB929102)the National Natural Science Foundation of China(Grant Nos.11104333 and 10974243)
文摘Superconducting nanowire single photon detector （SNSPD）, as a new type of superconducting single photon detector （SPD）, has a broad application prospect in quantum communication and other fields. In order to prepare SNSPD with high performance, it is necessary to fabricate a large area of uniform meander nanowires, which is the core of the SNSPD. In this paper, we demonstrate a process of patterning ultra-thin NbN films into meander-type nanowires by using the nano- imprint technology. In this process, a combination of hot embossing nano-imprint lithography （HE-NIL） and ultraviolet nano-imprint lithography （UV-NIL） is used to transfer the meander nanowire structure from the NIL Si hard mold to the NbN film. We have successfully obtained a NbN nanowire device with uniform line width. The critical temperature （Tc） of the superconducting NbN meander nanowires is about 5 K and the critical current （lc） is about 3.5 μA at 2.5 K.
文摘Ultra-thin (20-100nm) polymethylmethacrylate(PMMA) films prepared by Langmuir-Blodgett techniques have been explored as high resolution electron beam resists. A Hitachi S-450 Scanning Electron Microscope (SEM) has been refitted for a high resolution electron beam exposure system. The lithographic properties and exposure conditions of LB PMMA films were investigated. 0.15μm lines-and-spaces patterns were achieved by using the SEM as the exposure tool. The results demonstrate that the etch resistance of such films is sufficiently good to allow patterning of a 20 nm aluminum film suitable for mask fabrication.
