The Experts below are selected from a list of 314958 Experts worldwide ranked by ideXlab platform
Tadatomo Suga - One of the best experts on this subject based on the ideXlab platform.
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a comparison study direct wafer bonding of sic sic by standard Surface activated bonding and modified Surface activated bonding with si containing ar ion beam
Applied Physics Express, 2016Co-Authors: Fengwen Mu, Kenichi Iguchi, Haruo Nakazawa, Yoshikazu Takahashi, Masahisa Fujino, Ran He, Tadatomo SugaAbstract:In this study, the results of direct wafer bonding of SiC–SiC at room temperature by standard Surface-activated bonding (SAB) and modified SAB with a Si-containing Ar ion beam were compared, in terms of bonding energy, interface structure and composition, and the effects of rapid thermal annealing (RTA) at 1273 K in Ar gas. Compared with that obtained by the standard SAB, the bonding interface obtained by the modified SAB with a Si-containing Ar ion beam is ~30% stronger and almost completely recrystallized without oxidation during RTA, which should be due to the in situ Si compensation during Surface Activation by the Si-containing Ar ion beam.
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bonding of glass nanofluidic chips at room temperature by a one step Surface Activation using an o2 cf4 plasma treatment
Lab on a Chip, 2013Co-Authors: Yan Xu, Yiyang Dong, Lixiao Li, Kihoon Jang, Kazuma Mawatari, Tadatomo Suga, Chenxi Wang, Nobuhiro Matsumoto, Takehiko KitamoriAbstract:A technical bottleneck to the broadening of applications of glass nanofluidic chips is bonding, due to the strict conditions, especially the extremely high temperatures (∼1000 °C) and the high vacuum required in the current glass-to-glass fusion bonding method. Herein, we report a strong, nanostructure-friendly, and high pressure-resistant bonding method, performed at room temperature (RT, ∼25 °C) for glass nanofluidic chips, using a one-step Surface Activation process with an O2/CF4 gas mixture plasma treatment. The developed RT bonding method is believed to be able to conquer the technical bottleneck in bonding in nanofluidic fields.
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vapor assisted Surface Activation method for homo and heterogeneous bonding of cu sio 2 and polyimide at 150 c and atmospheric pressure
Journal of Electronic Materials, 2012Co-Authors: Akitsu Shigetou, Tadatomo SugaAbstract:Homo- and heterogeneous bonding of Cu, SiO2, and polyimide, by using a single vapor-assisted Surface Activation method at 150°C and atmospheric pressure, is highly feasible and will be of practical use in three-dimensional heterointegration of thin, flat interconnection layers. Since it is necessary to achieve good bondability to diverse materials in a single process in order to maintain bumpless structures, we have to create a compatible bridging layer. Bridging layers, based on Cu hydroxide hydrate and silanol and hydroxyl groups formed from SiO2 and polyimide, respectively, were prepared by introducing water onto the activated Surfaces at atmospheric pressure. The growth rate of the bridging layers was tunable via absolute humidity, and exposure of 8 g/m3 was used. Heating at 150°C, after exposure to humidity, caused tight adhesion between the mating Surfaces for all combinations of starting materials with voidless amorphous interfacial (bridging) layers. Because of the well-controlled layer thickness, low electrical resistivity of ∼4 × 10−8 Ω m was obtained at the Cu–Cu interface.
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low temperature direct bonding of glass nanofluidic chips using a two step plasma Surface Activation process
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Yiyang Dong, Lixiao Li, Kihoon Jang, Kazuma Mawatari, Tadatomo Suga, Yan Xu, Chenxi Wang, Takehiko KitamoriAbstract:Owing to the well-established nanochannel fabrication technology in 2D nanoscales with high resolution, reproducibility, and flexibility, glass is the leading, ideal, and unsubstitutable material for the fabrication of nanofluidic chips. However, high temperature (~1,000 °C) and a vacuum condition are usually required in the conventional fusion bonding process, unfortunately impeding the nanofluidic applications and even the development of the whole field of nanofluidics. We present a direct bonding of fused silica glass nanofluidic chips at low temperature, around 200 °C in ambient air, through a two-step plasma Surface Activation process which consists of an O2 reactive ion etching plasma treatment followed by a nitrogen microwave radical Activation. The low-temperature bonded glass nanofluidic chips not only had high bonding strength but also could work continuously without leakage during liquid introduction driven by air pressure even at 450 kPa, a very high pressure which can meet the requirements of most nanofluidic operations. Owing to the mild conditions required in the bonding process, the method has the potential to allow the integration of a range of functional elements into nanofluidic chips during manufacture, which is nearly impossible in the conventional high-temperature fusion bonding process. Therefore, we believe that the developed low-temperature bonding would be very useful and contribute to the field of nanofluidics.
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nanobonding technology toward electronic fluidic and photonic systems integration
IEEE Journal of Selected Topics in Quantum Electronics, 2011Co-Authors: Matiar M. R. Howlader, Ponnambalam Ravi Selvaganapathy, Jamal M Deen, Tadatomo SugaAbstract:In this paper, a review of Surface-Activation-based nanobonding technology for packaging and integration is presented. In this paper, the focus will be on nanobonding technology for electronic, photonic, and fluidic devices for miniaturized biomedical and environmental-sensing systems. We describe four different nanobonding techniques that have been developed and successfully implemented in a wide range of materials that include metals, semiconductors, flexible laminations, and ionic materials. Nanobonding technologies are particularly attractive because they offer void-free, strong, and nanoscale bonding at room temperature or at low temperature (<;200°C), and without the need for chemicals, adhesives, and high external pressure. Therefore, there are significant potential and opportunities for nanobonding technologies in the development of low cost, low loss, and high-speed miniaturized emerging systems based on a combination of electronic, fluidic, and photonic devices.
Mingyu Li - One of the best experts on this subject based on the ideXlab platform.
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silicon direct bonding via low temperature wet chemical Surface Activation
RSC Advances, 2016Co-Authors: Hongtao Chen, Mingyu LiAbstract:Commercial silicon substrates were bonded via low-temperature wet chemical Surface Activation in a standard laboratory without ultrahigh vacuum or a clean room. A smooth direct bond with no voids or microcracks was obtained, and the best bonding strength reached up to 4.15 MPa at 250 °C with the 25 MPa pressure-assisted process. The p–n junction prepared using this method exhibited excellent I–V characteristics. An updated model for the silicon direct bonding mechanism was proposed and proved. Raman scattering analysis indicated an increase in the Si–OH density on the silicon Surface after the Activation treatment. Cross-sectional HRTEM and EELS analysis crossing the interface indicated that the Si–O–Si linkage on the bonding interface that formed after low-temperature annealing was of a lower density than that of the native oxide. The thickness of the bonding interface decreased and the silicate linkage underwent further densification when high-temperature annealing was executed.
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low temperature direct bonding of silica glass via wet chemical Surface Activation
RSC Advances, 2015Co-Authors: Mingyu Li, Shihua YangAbstract:Silica glass pairs were directly bonded by wet chemical Surface Activation at a low temperature. A smooth joint interface with no voids and micro cracks was obtained with the assistance of a 250 °C heat treatment and a pressure of ∼30 MPa, and the excellent transmittance of the bonded pair was demonstrated by UV-Vis absorptions. This new method can tolerate a silica glass Surface roughness as high as 6 nm. A demo chip with a microfluidic channel was also prepared by this method. A modified model for the glass-to-glass bonding mechanism is proposed based on the Surface and interface characterization. Raman scattering analysis showed that Si–O–Si linkages at the silica glass Surface were broken, and colloid-like hydrolyzed layers formed on the glass Surface after the Activation treatment. TEM and EELS results revealed that the 3D glass structure of the Si–O–Si linkages formed again at the interface of the directly bonded silica glass pairs after low-temperature annealing.
Bernard P. Binks - One of the best experts on this subject based on the ideXlab platform.
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multiple phase inversion of emulsions stabilized by in situ Surface Activation of caco3 nanoparticles via adsorption of fatty acids
Langmuir, 2012Co-Authors: Bernard P. BinksAbstract:The in situ Surface Activation of raw CaCO3 nanoparticles by interaction with a series of sodium carboxylates of chain length between 6 and 12 as well as sodium 2-ethylhexylsulfosuccinate (AOT) was studied, and the impact of this on the stabilization and phase inversion of toluene–water emulsions was assessed. By using complementary experiments including measurement of particle zeta potentials, adsorption isotherms of amphiphile, and relevant contact angles, the mechanism of this Activation was revealed. The results show that hydrophilic CaCO3 nanoparticles can be Surface activated by interaction with sodium carboxylates and AOT even if they are not Surface-active themselves. Both the electrostatic interaction between the positive charges on particle Surfaces and the negative charges of anionic amphiphile headgroups and the chain–chain interactions of the amphiphile result in monolayer adsorption of the amphiphile at the particle–water interface. This transforms the particles from hydrophilic to partially...
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Aqueous foams stabilized by in situ Surface Activation of CaCO3 nanoparticles via adsorption of anionic surfactant.
Langmuir, 2010Co-Authors: Z Chen, Bernard P. BinksAbstract:The in situ Surface Activation of unmodified CaCO3 nanoparticles by interaction with surfactant in aqueous media has been studied, and the impact of this on the foamability and foam stability of aqueous dispersions was assessed. Using complementary experiments including measurement of particle zeta potentials, adsorption isotherms of surfactant, air−water Surface tensions, and relevant contact angles, the mechanism of this Activation was revealed. The results show that the non-Surface-active CaCO3 nanoparticles cannot be Surface activated by interaction with cationic or nonionic surfactants but can be Surface activated by interaction with anionic surfactants such as SDS and AOT, leading to a synergistic effect in both foamability and foam stability. The electrostatic interaction between the positive charges on particle Surfaces and the negative charges of anionic surfactant headgroups results in monolayer adsorption of the surfactant at the particle−water interface and transforms the particles from hydrop...
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effects of surfactant structure on the phase inversion of emulsions stabilized by mixtures of silica nanoparticles and cationic surfactant
Langmuir, 2010Co-Authors: L L Yang, Bernard P. BinksAbstract:Silica nanoparticles without any Surface modification are not Surface active at the toluene−water interface due to their extreme hydrophilicity but can be Surface activated in situ by adsorbing cationic surfactant from water. This work investigates the effects of the molecular structure of water-soluble cationic surfactant on the Surface Activation of the nanoparticles by emulsion characterization, adsorption and zeta potential measurements, dispersion stability experiments, and determination of relevant contact angles. The results show that an adsorbed cationic surfactant monolayer on particle Surfaces is responsible for the wettability modification of the particles. In the presence of a trace amount of cationic surfactant, the hydrophobicity of the particles increases, leading to the formation of stable oil-in-water O/W(1) emulsions. At high surfactant concentration (>cmc) the particle Surface is retransformed to hydrophilic due to double-layer or hemimicelle formation, and the concentration of the free...
Naoteru Shigekawa - One of the best experts on this subject based on the ideXlab platform.
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intrinsic microstructure of si gaas heterointerfaces fabricated by Surface activated bonding at room temperature
Japanese Journal of Applied Physics, 2018Co-Authors: Yutaka Ohno, Hideto Yoshida, Seiji Takeda, Jianbo Liang, Naoteru ShigekawaAbstract:The intrinsic microstructure of Si/GaAs heterointerfaces fabricated by Surface-activated bonding at room temperature is examined by plane-view transmission electron microscopy (TEM) and cross-sectional scanning TEM using damage-free TEM specimens prepared only by mechanochemical etching. The bonded heterointerfaces include an As-deficient crystalline GaAs layer with a thickness of less than 1 nm and an amorphous Si layer with a thickness of approximately 3 nm, introduced by the irradiation of an Ar atom beam for Surface Activation before bonding. It is speculated that the interface resistance mainly originates from the As-deficient defects in the former layer.
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electrical properties of si si interfaces by using Surface activated bonding
Journal of Applied Physics, 2013Co-Authors: Jianbo Liang, T Miyazaki, Masashi Morimoto, Shota Nishida, Naoteru ShigekawaAbstract:Electrical properties of n-Si/n-Si, p-Si/n-Si, and p−-Si/n+-Si junctions fabricated by using Surface-activated-bonding are investigated. The transmission electron microscopy/energy dispersive X-ray spectroscopy of the n-Si/n-Si interfaces reveals no evidence of oxide layers at the interfaces. From the current-voltage (I-V) and the capacitance-voltage (C-V) characteristics of the p-Si/n-Si and p−-Si/n+-Si junctions, it is found that the interface states, likely to have formed due to the Surface Activation process using Ar plasma, have a more marked impact on the electrical properties of the p-Si/n-Si junctions. An analysis of the temperature dependence of the I-V characteristics indicates that the properties of carrier transport across the bonding interfaces for reverse-bias voltages in the p-Si/n-Si and p−-Si/n+-Si junctions can be explained using the trap-assisted-tunneling and Frenkel-Poole models, respectively.
Shihua Yang - One of the best experts on this subject based on the ideXlab platform.
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low temperature direct bonding of silica glass via wet chemical Surface Activation
RSC Advances, 2015Co-Authors: Mingyu Li, Shihua YangAbstract:Silica glass pairs were directly bonded by wet chemical Surface Activation at a low temperature. A smooth joint interface with no voids and micro cracks was obtained with the assistance of a 250 °C heat treatment and a pressure of ∼30 MPa, and the excellent transmittance of the bonded pair was demonstrated by UV-Vis absorptions. This new method can tolerate a silica glass Surface roughness as high as 6 nm. A demo chip with a microfluidic channel was also prepared by this method. A modified model for the glass-to-glass bonding mechanism is proposed based on the Surface and interface characterization. Raman scattering analysis showed that Si–O–Si linkages at the silica glass Surface were broken, and colloid-like hydrolyzed layers formed on the glass Surface after the Activation treatment. TEM and EELS results revealed that the 3D glass structure of the Si–O–Si linkages formed again at the interface of the directly bonded silica glass pairs after low-temperature annealing.
