Plasmonic nanolithography based on cavity resonance through thick metal mask

Plasmonic lithography is a very promising fabrication technology to obtain nanoscale structures beyond the diffraction limit. In this paper, a new plasmonic lithography is proposed to realize high efficiency fabrication of arbitrary patterns, which is based on cavity resonance through a thick metal mask. The mechanism of the cavity resonance transmission is explored. The one dimension (1D) and two dimension (2D) printings are simulated and discussed. The simulated results show the method that provides potential to pattern feature size with at least 40 nm, about λ/11.     

Surface modification by intense proton irradiation

In the present paper the mixing of thin metal layers on silicon or copper substrates induced by HIPIB (High Intensituy Pulsed Ion Beams) was investigated using a device which delivers mainly protons with a maximum ion energy of E ₀=250 keV, a pulse length of =50 ns, and an energy density per pulse of 3 J/cm². The temperature distribution in the samples which was evaluated by solving the one-dimensional heat-flow equation indicates that 1 m layers are heated well above the melting point. The samples were analysed by RBS (Rutherford Backscattering Spectrometry), SNMS (Sputtered Neutral Mass Spectrometry), X-ray diffraction and a microprobe. If the surface tension of the molten layer is larger than the one of the substrate, the layer material is splashed off. Chromium layers on copper are completely mixed after irradiation by a few shots and a considerable hardening of the surface is observed.     

激光干涉光刻法制作100 nm掩模

介绍了一种利用激光干涉光刻技术得到特征图形,并通过离子束刻蚀将图形转移到铬层上,从而获得掩模的方法。针对掩模透光率以及对干涉图形对比度可能产生影响的两个参数分别进行了数值仿真,从而证明此方法的可行性和参数的优化选择。自搭干涉光刻实验系统,用257 nm的激光光源实现光刻,得到特征尺寸为100 nm的图形,再经过离子束刻蚀,最终得到周期200 nm、线宽100 nm的掩模。     

激光干涉光刻法制作100 nm掩模

 介绍了一种利用激光干涉光刻技术得到特征图形,并通过离子束刻蚀将图形转移到铬层上,从而获得掩模的方法。针对掩模透光率以及对干涉图形对比度可能产生影响的两个参数分别进行了数值仿真,从而证明此方法的可行性和参数的优化选择。自搭干涉光刻实验系统,用257 nm的激光光源实现光刻,得到特征尺寸为100 nm的图形,再经过离子束刻蚀,最终得到周期200 nm、线宽100 nm的掩模。     

Modification of polyethylene terephthalate by proton irradiation

Polyethylene terephthalate (PET) films were irradiated with 3 MeV proton beams at different fluences. The microhardness, electrical, thermal and structural studies were carried out using microhardness tester, LCR meter, thermogravimetric analysis (TGA) and FTIR spectroscopy. Vickers' hardness has been observed to increase with the fluence. The true bulk hardness of the film was obtained at loads greater than 400 mN. The AC electrical conductivity is practically unaffected by irradiation up to a frequency of 10 kHz, but it is found to increase exponentially at a frequency of 300 kHz. The loss factor and dielectric constant are observed to change appreciably with the fluence. It is observed that there is no significant change in the stability of the polymer up to the fluence of 10¹⁴ ions cm^?2 as revealed by TGA and FTIR spectroscopy.     

Theoretical study of magnetic pattern replication by He+ ion irradiation through stencil masks

We have developed an irradiation technique that allows us to tune the magnetic properties of Co/Pt multilayers without affecting their roughness. The planarity and the ability to independently control nanostructure size and coercivity make our technique very appealing for magnetic recording. We study the irradiation-induced 1:1 replication of features drilled in a stencil mask. Both the “gap” G between the magnetic film and the mask, and the aspect ratio (AR) of the mask features are analyzed, in view of the ion straggling in the mask resulting in collateral damages. Optimal gap is such that D⪡G⪡D/tan(α) (typically 0.1⪡G⪡25 μm), where the D is the feature size. The replication quality is best for AR⩾3. Since the allowed gap interval is wide, we anticipate that mask fast positioning will be possible for the applications to magnetic recording.     

Fabrication of porous metal fiber sintered sheet as a flow field for proton exchange membrane fuel cell

To improve the diffusion performance of reactive gas, a porous copper fiber sintered sheet (PCFSS) was fabricated and used as the flow field for proton exchange membrane fuel cell (PEMFC). The pressure and flow velocity distribution of the reaction gas in the PCFSS was firstly compared with the serpentine flow field by using the Fluent simulation software. Our results showed that the superiority of PCFSS in the uniformity of gas diffusion was observed. The total resistance of PEMFC with PCFSS in different porosities was obtained. And the advantages of PCFSS in electronic transmission were found by comparing with the serpentine flow field. Besides, the influences of different operating conditions and different porosities of porous flow fields on the performance of PEMFC were experimentally investigated. With the cell temperature of 70 °C as well as the humidification temperature of 60 °C, a PEMFC with PCFSS of 70% porosity exhibited better performance.     

Fabrication of large-scale ultra-smooth metal surfaces by a replica technique

The IR double-resonance techniques IR/R2PI (infrared/resonant 2-photon ionization), IR/PIRI (infrared-photo-induced Rydberg ionization) and IR-photodissociation spectroscopy are valuable tools to investigate structure, vibrations, and dynamical processes of neutral and ionic hydrogen-bonded clusters containing aromatic molecules. In this paper we report on the application of the IR double-resonance techniques to determine the NH and OH stretching vibrations of 4-aminophenol and 4-aminophenol(H₂O)₁, both in the neutral (S₀) and ionic (D₀) ground state. All vibrational frequencies obtained for 4-aminophenol and the cluster are compared with the values obtained from ab initio and DFT calculations. In the S₀ state, a trans-linear arrangement of 4-aminophenol(H₂O)₁ is obtained containing an O-H·· O hydrogen bond. In the D₀ state an overlay of two spectra can be observed resulting from the trans-linear structure and a second structure which contains a N-H·· O hydrogen bond. The observation of these two structures within the ion is an interesting example of a rearrangement reaction in the ionic state. Received: 3 November 2000 / Accepted: 6 November 2000 / Published online: 9 February 2001     

Modulation of HTSC characteristics induced by proton irradiation

Il Nuovo Cimento D - Bulk slabs of sintered YBCO were irradiated with monoenergetic protons at different energies (3.5 and 6.5 MeV) and different fluences, ranging from 1.8·1016 to...     

Surface modification of magnetic metal nanoparticles through irradiation graft polymerization

To tailor the interfacial interaction in magnetic metal nanoparticles filled polymer composites, the surfaces of iron, cobalt and nickel nanoparticles were grafted by irradiation polymerization. In the current report, effects of grafting conditions, including irradiation atmosphere, irradiation dose and monomer concentration, on the grafting reaction are presented. The interaction between the nanoparticles and the grafted polymer was studied by thermal analysis and X-ray photoelectron spectrometry. It was found that there is a strong interfacial interaction in the form of electrostatic bonding in the polymer-grafted nanoparticles. The dispersibility of the modified nanoparticles in chloroform was significantly improved due to the increased hydrophobicity.     

Some features of phase transformations induced by selective removal of oxygen atoms from metal oxides under proton irradiation

It has been shown that oxygen atoms are selectively removed from metal oxides under ～ 1 keV proton irradiation. The reduced metallic layer thickness reaches several tens of nanometers. The reduction of metal from oxide is accompanied by significant volume changes, the value of which has been experimentally determined and compared to theoretical estimates. It has been found that the metal reduction process can be carried out through an additional upper (relative to the proton beam) layer. It has been shown that the metal reduction rate does not change in the case of a thin (～5 nm) upper layer; however, the coercive force of ferromagnetic metals increases strongly.     

Induced magnetic ordering by proton irradiation in graphite

We provide evidence that proton irradiation of energy 2.25 MeV on highly oriented pyrolytic graphite samples triggers ferro- or ferrimagnetism. Measurements performed with a superconducting quantum interferometer device and magnetic force microscopy reveal that the magnetic ordering is stable at room temperature.     

利用金属掩模法制备钉扎型磁性隧道结

利用金属掩模法和Ir22Mn78合金反铁磁钉扎层，制备了四种钉扎型的Py/Al2O3/Py，Py/Al2O3/Co，Co/Al2O3/Py和Co/Al2O3/Co磁性隧道结，坡莫合金的成分为Py＝Ni79Fe21.例如：利用狭缝宽度为100?μm的金属掩模，直接制备出室温隧穿磁电阻比值为17.2%的磁性隧道结Co/Al2O3/Co，其结电阻为76Ω,结电阻和结面积的积矢为76×10_{4Ωμm2，自由层的偏转场为1114?A/m，并且在外加磁场0.1114A·m-1之间时室温磁电阻比值 关键词： 磁性隧道结 隧穿磁电阻 磁随机存储器 金属掩模}     

Fabrication of 3D metal/polymer microstructures by site-selective metal coating

Three-dimensional silver/polymer conjugated microstructures were fabricated by site-selective metal deposition on photopolymer structures in the sub-micrometer scale. Photopolymerizable resins with and without an amide group were independently prepared, and a three-dimensional polymer structure was fabricated with those resins by means of the two-photon-induced photopolymerization technique to confine the photopolymerization to a sub-micrometer volume. Silver was selectively deposited on the surface of the amide-containing polymer parts by electroless plating. This method can provide 3D arbitrary silver/polymer composite microstructures with sub-micrometer resolution. PACS 81.07-b; 81.16-c; 81.07.Pr     

Formation of noble metal particles by ultrasonic irradiation

It was found that sonochemically prepared metal particles such as Ag, Pd, Au, Pt and Rh are of nanometer size with a fairly narrow distribution (e.g., about 5 nm for Pd particles obtained from a 1.0 mM Pd(II) in polyethylene glycol monostearate solution). We have suggested three different reduction pathways under sonication: (i) reduction by H atoms, (ii) reduction by secondary reducing radicals formed by hydrogen abstraction from organic additives with OH radicals and H atoms, (iii) reduction by radicals formed from pyrolysis of the additives at the interfacial region between cavitation bubbles and the bulk solution. The reduction of Ag(I) and Pt(II) mainly proceeds through reaction pathway (ii). In the cases of Pd(II) and Au(III), the reductions mainly proceed through reaction pathway (iii). The reduction of Rh(III) was not achieved under the same conditions; however, by the addition of sodium formate, reduction occurred and the preparation of Rh particles succeeded.