The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Yutaka Majima - One of the best experts on this subject based on the ideXlab platform.
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gap separation controlled nanogap electrodes by molecular ruler electroless Gold Plating
RSC Advances, 2015Co-Authors: Victor M Serdio, Toshiharu Teranishi, Taro Muraki, Shuhei Takeshita, Daniel Hurtado E S, Shinya Kano, Yutaka MajimaAbstract:A simultaneous fabrication process of multiple nanogap electrodes at desired gap separations by the technique of molecular ruler electroless Gold Plating (MoREP) is reported. Initial Gold nanogap electrodes with a gap separation of 22 nm were immersed into MoREP solutions consisting of chloroauric acid, surfactant molecules of alkyltrimethylammonium bromide (CnTAB, n = 12–18) and ascorbic acid as a reducing agent. The electroless Plating locally self-terminates between the gap when the surfactant molecules physisorbed to the surface of one electrode interdigitate with the ones of the opposite electrode. The mean nanogap separation correlated with the alkyl chain length, and can be controlled between 2.5 ± 0.6 and 3.3 ± 0.8 nm by choosing the alkyl chain length of the surfactant molecules (C12–C18). A double-gate single-electron transistor (SET) was chemically assembled by introducing chemically a synthesized Gold nanoparticle into the MoREP nanogap electrodes, and showed stable Coulomb diamonds under application of both gate voltages.
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robust nanogap electrodes by self terminating electroless Gold Plating
Nanoscale, 2012Co-Authors: Victor M Serdio, Toshiharu Teranishi, Yutaka Majima, Taro Muraki, Shuhei Takeshita, Yasuo AzumaAbstract:Robust nanogap electrodes for nanodevices with a separation of 3.0 ± 1.7 nm were simultaneously mass-produced at a yield of 90% by a combination of electron beam lithography (EBL) and electroless Gold Plating (EGP). Nanogap electrodes demonstrated their robustness as they maintained their structure unchanged up to temperatures of 170 °C, during the isotropic oxygen plasma ashing removal of the amorphous carbon overlayer resulting from scanning electron microscopy observations, therefore maintaining their surface reactivity for EGP and formation of a self-assembled monolayer. A Gold layer grows over the electrode surface during EGP, narrowing the separation between the electrodes; growth stops around 3 nm due to a self-termination phenomenon. This is the main factor in the high yield and reproducibility of the EGP process because it prevents contact between the electrodes. A 90% yield is achieved by also controlling the etching and physisorption of Gold clusters, which is accomplished by reduction of triiodide ions and heat treatment of the EGP solution, respectively. A mixed self-assembled monolayer of octanethiol and decanedithiol can be formed at the surface of the nanogap electrodes after the oxygen plasma treatment, and decanethiol-protected Au nanoparticles were chemisorbed between the self-terminated nanogap electrodes via decanedithiol. Chemically assembled single-electron transistors based on the nanogap electrodes exhibit ideal, stable, and reproducible Coulomb diamonds.
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simultaneous fabrication of nanogap Gold electrodes by electroless Gold Plating using a common medical liquid
Applied Physics Letters, 2007Co-Authors: Yuhsuke Yasutake, Keijiro Kono, Masayuki Kanehara, Toshiharu Teranishi, M R Buitelaar, C G Smith, Yutaka MajimaAbstract:We report a simple and high yield method for fabricating multiple nanogaps simultaneously by an electroless Gold Plating technique using electroless Gold Plating solution which consists of common medical liquid of iodine tincture and L(+)-ascorbic acid (vitamin C). The distance between the Gold electrodes (33nm in average) on the SiO2∕Si substrate was decreased by selective deposition of Gold onto the surface of the Gold electrodes. By electroless Gold Plating, we fabricated nanogaps below 5nm in width with a 41% process yield. We also demonstrated the Coulomb blockade effect in octanethiol(C8)-protected Au nanoparticles by using such a fabricated nanogap.
Zhenghe Feng - One of the best experts on this subject based on the ideXlab platform.
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air filled long slot leaky wave antenna based on folded half mode waveguide using silicon bulk micromachining technology for millimeter wave band
IEEE Transactions on Antennas and Propagation, 2017Co-Authors: Le Chang, Zhijun Zhang, Yue Li, Shaodong Wang, Zhenghe FengAbstract:An air-filled long slot leaky-wave antenna (LWA) based on folded half-mode waveguide (FHMW) fabricated using silicon substrate is proposed for millimeter-wave application. As is well known, the high-permittivity silicon dielectric is not suitable for antenna design. Thanks to the through-wafer dry etching and Gold-Plating processes deriving from the silicon bulk micromachining technology, three purely air-filled structures including the vertical part of the FHMW that also acts as the leaky-wave long slot in the top layer, horizontal part of the FHMW and matching section in the middle layer, and coupling slot in the bottom layer constitute the high-performance air-filled long slot LWA. To the best of the authors’ knowledge, this is the first time that an FHMW is adopted for antenna design. Compared with the conventional half-mode waveguide, the profile is lowered, the required silicon layer number is fixed to three, and the design can be more flexible. Experiment of the fabricated prototype shows that the main beam can be scanned from 41° to 49° with a gain variation between 13.15 and 15.41 dBi in the frequency range from 56 to 64 GHz. Moreover, confirmation of the design strategy provides the feasibility to realize the system-in-package solution.
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60 ghz air substrate leaky wave antenna based on mems micromachining technology
IEEE Transactions on Components Packaging and Manufacturing Technology, 2016Co-Authors: Le Chang, Zhijun Zhang, Yue Li, Shaodong Wang, Zhenghe FengAbstract:In this paper, a 60-GHz air substrate leaky-wave antenna based on microelectromechanical system (MEMS) bulk micromachining is proposed. Using penetration dry etching and Gold Plating processes, the air-filled leaky-wave slots, waveguide, and coupling slot, which are located in the top, middle, and bottom silicon-based layers, respectively, are generated. The three layers are stacked and clamped together using two location pins and five metal screws. The most distinctive feature of the proposed antenna is that the electromagnetic wave cannot see any substrates, except for the air medium, leading to good antenna performance. Good agreement between simulation and measurement demonstrates that the MEMS micromachining process fulfills the millimeter-wave (mm-wave) accuracy. To the best of the authors’ knowledge, this is the first time that an air substrate mm-wave antenna is fabricated using the MEMS bulk micromachining technology. The fabricated prototype with a bandwidth of 17.3% and a peak gain of 11.4 dBi is attractive for mm-wave wireless communication applications. Validity of the feasibility provides the possibility to realize the system-in-package solutions.
Hongyuan Chen - One of the best experts on this subject based on the ideXlab platform.
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thermal plasma driven reversible wettability switching of a bare Gold film on a poly dimethylsiloxane surface by electroless Plating
Langmuir, 2010Co-Authors: Haijing Bai, Xianbo Zhang, Hongyuan ChenAbstract:We report an approach for fabricating a tunable wettability surface by electroless Gold Plating on poly(dimethylsiloxane) (PDMS). A two-layer structured Gold film with a tight layer and a loose lay...
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patterned au poly dimethylsiloxane substrate fabricated by chemical Plating coupled with electrochemical etching for cell patterning
Langmuir, 2009Co-Authors: Minling Shao, Jingjuan Xu, Hongyuan ChenAbstract:In this paper, we present a novel approach for preparing patterned Au/poly(dimethylsiloxane) (PDMS) substrate. Chemical Gold Plating instead of conventional metal evaporation or sputtering was introduced to achieve a homogeneous Gold layer on native PDMS for the first time, which possesses low-cost and simple operation. An electrochemical oxidation reaction accompanied by the coordination of Gold and chloride anion was then exploited to etch Gold across the region covered by electrolyte. On the basis of such an electrochemical etching, heterogeneous Au/PDMS substrate which has a Gold “island” pattern or PDMS dots pattern was fabricated. Hydrogen bubbles which were generated in the etching process due to water electrolysis were used to produce a safe region under the Pt auxiliary electrode. The safe region would protect Gold film from etching and lead to the formation of the Gold “island” pattern. In virtue of a PDMS stencil with holes array, Gold could be etched from the exposed region and take on the PDM...
Le Chang - One of the best experts on this subject based on the ideXlab platform.
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air filled long slot leaky wave antenna based on folded half mode waveguide using silicon bulk micromachining technology for millimeter wave band
IEEE Transactions on Antennas and Propagation, 2017Co-Authors: Le Chang, Zhijun Zhang, Yue Li, Shaodong Wang, Zhenghe FengAbstract:An air-filled long slot leaky-wave antenna (LWA) based on folded half-mode waveguide (FHMW) fabricated using silicon substrate is proposed for millimeter-wave application. As is well known, the high-permittivity silicon dielectric is not suitable for antenna design. Thanks to the through-wafer dry etching and Gold-Plating processes deriving from the silicon bulk micromachining technology, three purely air-filled structures including the vertical part of the FHMW that also acts as the leaky-wave long slot in the top layer, horizontal part of the FHMW and matching section in the middle layer, and coupling slot in the bottom layer constitute the high-performance air-filled long slot LWA. To the best of the authors’ knowledge, this is the first time that an FHMW is adopted for antenna design. Compared with the conventional half-mode waveguide, the profile is lowered, the required silicon layer number is fixed to three, and the design can be more flexible. Experiment of the fabricated prototype shows that the main beam can be scanned from 41° to 49° with a gain variation between 13.15 and 15.41 dBi in the frequency range from 56 to 64 GHz. Moreover, confirmation of the design strategy provides the feasibility to realize the system-in-package solution.
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60 ghz air substrate leaky wave antenna based on mems micromachining technology
IEEE Transactions on Components Packaging and Manufacturing Technology, 2016Co-Authors: Le Chang, Zhijun Zhang, Yue Li, Shaodong Wang, Zhenghe FengAbstract:In this paper, a 60-GHz air substrate leaky-wave antenna based on microelectromechanical system (MEMS) bulk micromachining is proposed. Using penetration dry etching and Gold Plating processes, the air-filled leaky-wave slots, waveguide, and coupling slot, which are located in the top, middle, and bottom silicon-based layers, respectively, are generated. The three layers are stacked and clamped together using two location pins and five metal screws. The most distinctive feature of the proposed antenna is that the electromagnetic wave cannot see any substrates, except for the air medium, leading to good antenna performance. Good agreement between simulation and measurement demonstrates that the MEMS micromachining process fulfills the millimeter-wave (mm-wave) accuracy. To the best of the authors’ knowledge, this is the first time that an air substrate mm-wave antenna is fabricated using the MEMS bulk micromachining technology. The fabricated prototype with a bandwidth of 17.3% and a peak gain of 11.4 dBi is attractive for mm-wave wireless communication applications. Validity of the feasibility provides the possibility to realize the system-in-package solutions.
Toshiharu Teranishi - One of the best experts on this subject based on the ideXlab platform.
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gap separation controlled nanogap electrodes by molecular ruler electroless Gold Plating
RSC Advances, 2015Co-Authors: Victor M Serdio, Toshiharu Teranishi, Taro Muraki, Shuhei Takeshita, Daniel Hurtado E S, Shinya Kano, Yutaka MajimaAbstract:A simultaneous fabrication process of multiple nanogap electrodes at desired gap separations by the technique of molecular ruler electroless Gold Plating (MoREP) is reported. Initial Gold nanogap electrodes with a gap separation of 22 nm were immersed into MoREP solutions consisting of chloroauric acid, surfactant molecules of alkyltrimethylammonium bromide (CnTAB, n = 12–18) and ascorbic acid as a reducing agent. The electroless Plating locally self-terminates between the gap when the surfactant molecules physisorbed to the surface of one electrode interdigitate with the ones of the opposite electrode. The mean nanogap separation correlated with the alkyl chain length, and can be controlled between 2.5 ± 0.6 and 3.3 ± 0.8 nm by choosing the alkyl chain length of the surfactant molecules (C12–C18). A double-gate single-electron transistor (SET) was chemically assembled by introducing chemically a synthesized Gold nanoparticle into the MoREP nanogap electrodes, and showed stable Coulomb diamonds under application of both gate voltages.
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robust nanogap electrodes by self terminating electroless Gold Plating
Nanoscale, 2012Co-Authors: Victor M Serdio, Toshiharu Teranishi, Yutaka Majima, Taro Muraki, Shuhei Takeshita, Yasuo AzumaAbstract:Robust nanogap electrodes for nanodevices with a separation of 3.0 ± 1.7 nm were simultaneously mass-produced at a yield of 90% by a combination of electron beam lithography (EBL) and electroless Gold Plating (EGP). Nanogap electrodes demonstrated their robustness as they maintained their structure unchanged up to temperatures of 170 °C, during the isotropic oxygen plasma ashing removal of the amorphous carbon overlayer resulting from scanning electron microscopy observations, therefore maintaining their surface reactivity for EGP and formation of a self-assembled monolayer. A Gold layer grows over the electrode surface during EGP, narrowing the separation between the electrodes; growth stops around 3 nm due to a self-termination phenomenon. This is the main factor in the high yield and reproducibility of the EGP process because it prevents contact between the electrodes. A 90% yield is achieved by also controlling the etching and physisorption of Gold clusters, which is accomplished by reduction of triiodide ions and heat treatment of the EGP solution, respectively. A mixed self-assembled monolayer of octanethiol and decanedithiol can be formed at the surface of the nanogap electrodes after the oxygen plasma treatment, and decanethiol-protected Au nanoparticles were chemisorbed between the self-terminated nanogap electrodes via decanedithiol. Chemically assembled single-electron transistors based on the nanogap electrodes exhibit ideal, stable, and reproducible Coulomb diamonds.
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simultaneous fabrication of nanogap Gold electrodes by electroless Gold Plating using a common medical liquid
Applied Physics Letters, 2007Co-Authors: Yuhsuke Yasutake, Keijiro Kono, Masayuki Kanehara, Toshiharu Teranishi, M R Buitelaar, C G Smith, Yutaka MajimaAbstract:We report a simple and high yield method for fabricating multiple nanogaps simultaneously by an electroless Gold Plating technique using electroless Gold Plating solution which consists of common medical liquid of iodine tincture and L(+)-ascorbic acid (vitamin C). The distance between the Gold electrodes (33nm in average) on the SiO2∕Si substrate was decreased by selective deposition of Gold onto the surface of the Gold electrodes. By electroless Gold Plating, we fabricated nanogaps below 5nm in width with a 41% process yield. We also demonstrated the Coulomb blockade effect in octanethiol(C8)-protected Au nanoparticles by using such a fabricated nanogap.