共查询到20条相似文献,搜索用时 31 毫秒
1.
T. Senn Ch. WaberskiJ. Wolf J.P. EsquivelN. Sabaté B. Löchel 《Microelectronic Engineering》2011,88(1):11-16
A new technique for the realization of complex three dimensional (3D) structures in polymer materials is presented. The described process can be applied for the fabrication of 3D structured foils as well as for 3D structured polymer parts using a replica molding process. In the first step, the foil is structured by Hot Embossing. This structured foil is then blown into a structured mold by pressure at high temperature, using a thermoforming process. The thermoforming process is realized in an especially designed tool, where different mold inserts can be applied. In the thermoforming process this tool, containing the mold insert and the structured foil is heated up and a pressure is applied which assures, that the foil covers the structured mold insert. Due to parameter optimization, high pattern fidelity can be achieved. As structures a porefield with a pore diameter of 500 nm and lines and spaces with a width of 1.6 μm were used. Besides a Moth Eye structure with a period of 280 nm and a blazed grating with a period of 1 μm and a blazed angle of 15° were imprinted and blown into the structured mold. The results show, that this process can be used to fabricate 3D structured foils with good structure fidelity. Besides the structured foils, additional poly(dimethylsiloxane) (PDMS) replications can be made out of this foils. These PDMS replications are used as stamps in a replica molding process. A micro fluidic system containing hydrophobic and hydrophilic channels was created using this process. 相似文献
2.
三级微纳超疏水表面的超快激光复合制备及防除冰性能研究 总被引:4,自引:0,他引:4
本文针对超疏水表面的防除冰性能,采用超快激光结合化学氧化的复合制备方法,开发了一类新的三级微纳超疏水表面结构,这类结构由微米锥阵列支撑结构以及在其上密集生长的金属氧化物纳米草结构和弥散分布的微米或亚微米花结构组合而成。经过表面改性后,这类三级微纳结构具有优异的超疏水性,其接触角可超过160°,滚动角在1°以内。对这类三级微纳超疏水表面的防结冰性能进行研究后发现,在冷凝和低温环境下,该类超疏水表面存在合并诱导自跳跃以及分级冷凝的现象,分级冷凝不仅可使表面上的一级冷凝液滴在高湿度环境下依然保持Cassie状态,还能使液滴在结冰前脱离表面,因此具有较好的防结冰性能;此外,由于表面三级微纳粗糙结构中捕获的空气囊具有较好的隔热作用,因此该超疏水表面具有良好的延迟结冰性能,其延迟异质形核的时间达到了52 min 39 s。最后,本文对三级微纳超疏水表面的疏冰性能进行了研究,结果表明:三级微纳超疏水表面的冰粘附强度仅为6 kPa,约为未经处理的铝合金表面的1/40;经过10次推冰测试后,该超疏水表面的冰粘附强度依然不超过20 kPa,说明该表面具有良好的机械耐久性,应用潜力巨大。 相似文献
3.
为解决航空器在各种运行环境环境中可能出现的霜冰影响问题,利用微秒脉冲激光在钛合金表面制备了超疏水表面,并通过微观形貌、表面元素组成、润湿性和结霜实验等对超疏水效果和抑霜性能进行了分析表征。实验结果表明,微秒激光制备的不同扫描间距的微纳结构表面均达到了超疏水效果,其中扫描间距为0.2 mm的表面接触角可达159°,其表面激光作用形成的大量细小颗粒以及溅落的碎屑等形成的亚微米和纳米级结构,为空气中有机疏水基团提供了丰富的结合位点,二者共同带来了表面优良的超疏水性能,表面生长的霜层薄,霜枝较高,十分有利于外界作用清除。本方法可为航空领域霜冰问题的解决提供一定参考。 相似文献
4.
Jose Marquez-Velasco Maria-Elena Vlachopoulou Angeliki Tserepi Evangelos Gogolides 《Microelectronic Engineering》2010,87(5-8):782-785
SU-8 is a photosensitive resist widely used for the fabrication of MEMS and lab-on-a-chip devices, as well as of model structures for testing wetting theories. In this work, superhydrophobic surfaces are fabricated on SU-8 by combining micro- and nano-sized structures formed by means of lithography and plasma etching, respectively. It is found that nanotexturing of the micropatterned SU-8 surfaces is essential in enhancing surface hydrophobicity and rendering the surfaces water repellent (i.e. minimizing contact angle hysteresis). The proposed method will be shown to be of paramount importance for the fabrication of mechanically stable and robust superhydrophobic SU-8 surfaces with low aspect ratio microstructuring. 相似文献
5.
C. Ingrosso V. Fakhfouri M. Striccoli A. Agostiano A. Voigt G. Gruetzner M. L. Curri J. Brugger 《Advanced functional materials》2007,17(13)
M. Lucia Curri and co‐workers report on p. 2009 an epoxy‐based negative tone photoresist that can be functionalized with red emitting CdSe@ZnS core/shell type nanocrystals and patterned by UV lithography. The 3D high aspect ratio of the microfabricated structures proves that lithographic properties of the functional nanocomposite are retained and the nanocrystals properties conveyed into the resist. The emitting nanocomposite represents a convenient model for material functionalization expandable to nanocrystals with different properties. An epoxy‐based negative‐tone photoresist, which is known as a suitable material for high‐aspect‐ratio surface micromachining, is functionalized with red‐light‐emitting CdSe@ZnS nanocrystals (NCs). The proper selection of a common solvent for the NCs and the resist is found to be critical for the efficient incorporation of the NCs in the epoxy matrix. The NC‐modified resist can be patterned by standard UV lithography down to micrometer‐scale resolution, and high‐aspect‐ratio structures have been successfully fabricated on a 100 mm scaled wafer. The “as‐fabricated”, 3D, epoxy‐based surface microstructures show the characteristic luminescent properties of the embedded NCs, as verified by fluorescence microscopy. This issue demonstrates that the NC emission properties can be conveniently conveyed into the polymer matrix without deteriorating the lithographic performance of the latter. The dimensions, the resolution, and the surface morphology of the NC‐modified‐epoxy microstructures exhibit only minor deviations with respect to that of the unmodified reference material, as examined by means of microscopic and metrologic investigations. The proposed approach of the incorporation of emitting and non‐bleachable NCs into a photoresist opens novel routes for surface patterning of integrated microsystems with inherent photonic functionality at the micro‐ and nanometer‐scale for light sensing and emitting applications. 相似文献
6.
7.
Large area nanosize array stamp for UV-based nanoimprint lithography fabricated by size reduction process 总被引:1,自引:0,他引:1
Xiaoli Li Qingkang Wang Jing Zhang Weimin Zhou Yanbo Liu Yongzhong Wan Xiaoming Niu 《Microelectronic Engineering》2009,86(10):2015-2019
A novel size reduction process using electron beam lithography (EBL) combining with wet etching technique is developed as a possible solution for producing large area and low cost nanopattern stamp for UV-based nanoimprint lithography (UV-NIL). In the first step, a microstructure stamp with 1.4 μm periodical pore array and aspect ratio of 1:1 was formed over a 1 inch2 area on a quartz substrate. This process was carried out using common electron beam lithography (EBL) equipment, which was easily available in the modern integrated circuits (IC) semiconductor factory. Afterwards, with a controlled wet etching technique, the pore array was changed into tip patterns with the line width below 100 nm and the period keeping as before. The uniformities and nanopattern accuracies were investigated to identify its possibility as a UV-NIL stamp by AFM and SEM. Finally, as a demonstration, the as obtained stamp was used as a positive stamp to replicate the nanotips into UV-curable resist successfully by a UV-NIL process. The method developed for the mold of nanoimprint lithography would be a simple and low price approach to fabricate large area UV-NIL stamp and the nanotip array structures would be widely used in two dimensional (2D) photonic crystal application. 相似文献
8.
Surface Energy‐Controlled SERS Substrates for Molecular Concentration at Plasmonic Nanogaps
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Sung‐Gyu Park ChaeWon Mun Xiaofei Xiao Avi Braun Sunho Kim Vincenzo Giannini Stefan A. Maier Dong‐Ho Kim 《Advanced functional materials》2017,27(41)
Positioning probe molecules at electromagnetic hot spots with nanometer precision is required to achieve highly sensitive and reproducible surface‐enhanced Raman spectroscopy (SERS) analysis. In this article, molecular positioning at plasmonic nanogaps is reported using a high aspect ratio (HAR) plasmonic nanopillar array with a controlled surface energy. A large‐area HAR plasmonic nanopillar array is generated using a nanolithography‐free simple process involving Ar plasma treatment applied to a smooth polymer surface and the subsequent evaporation of metal onto the polymer nanopillars. The surface energy can be precisely controlled through the selective removal of an adsorbed self‐assembled monolayer of low surface‐energy molecules prepared on the plasmonic nanopillars. This process can be used to tune the surface energy and provide a superhydrophobic surface with a water contact angle of 165.8° on the one hand or a hydrophilic surface with a water contact angle of 40.0° on the other. The highly tunable surface wettability is employed to systematically investigate the effects of the surface energy on the capillary‐force‐induced clustering among the HAR plasmonic nanopillars as well as on molecular concentration at the collapsed nanogaps present at the tops of the clustered nanopillars. 相似文献
9.
Jun Taniguchi Yasuhiro Kamiya Takeshi Ohsaki Nobuji Sakai 《Microelectronic Engineering》2010,87(5-8):859-863
Ultraviolet nanoimprint lithography (UV-NIL) is a powerful tool for nanoscale fabrication. However, the replication of high-density, high-aspect-ratio mold patterns by UV-NIL is very difficult because of the strong forces required to release the replicate from the mold. We used a glassy carbon (GC) mold with an antireflective structure, fabricated by irradiation with an oxygen-ion beam, to produce a high-density, high-aspect-ratio pattern, and we evaluated its release properties. The fabricated GC surface contained high-aspect-ratio conical structures with pitch of less than 100 nm. After fabrication of the antireflective structure, the mold surface was coated with chromium and a fluorinated silane coupling agent. By using this treatment and a peel motion during mold release, faithful replication of the mold structure in photocurable resin was possible. The release force increased with increasing mold surface area; the surface area effect is therefore the main factor in the mold-release step. 相似文献
10.
C. Ingrosso V. Fakhfouri M. Striccoli A. Agostiano A. Voigt G. Gruetzner M. L. Curri J. Brugger 《Advanced functional materials》2007,17(13):2009-2017
An epoxy‐based negative‐tone photoresist, which is known as a suitable material for high‐aspect‐ratio surface micromachining, is functionalized with red‐light‐emitting CdSe@ZnS nanocrystals (NCs). The proper selection of a common solvent for the NCs and the resist is found to be critical for the efficient incorporation of the NCs in the epoxy matrix. The NC‐modified resist can be patterned by standard UV lithography down to micrometer‐scale resolution, and high‐aspect‐ratio structures have been successfully fabricated on a 100 mm scaled wafer. The “as‐fabricated”, 3D, epoxy‐based surface microstructures show the characteristic luminescent properties of the embedded NCs, as verified by fluorescence microscopy. This issue demonstrates that the NC emission properties can be conveniently conveyed into the polymer matrix without deteriorating the lithographic performance of the latter. The dimensions, the resolution, and the surface morphology of the NC‐modified‐epoxy microstructures exhibit only minor deviations with respect to that of the unmodified reference material, as examined by means of microscopic and metrologic investigations. The proposed approach of the incorporation of emitting and non‐bleachable NCs into a photoresist opens novel routes for surface patterning of integrated microsystems with inherent photonic functionality at the micro‐ and nanometer‐scale for light sensing and emitting applications. 相似文献
11.
Fine‐Tuning of Superhydrophobicity Based on Monolayers of Well‐defined Raspberry Nanoparticles with Variable Dual‐roughness Size and Ratio
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Camille C. M. C. Carcouët A. Catarina C. Esteves Marco M. R. M. Hendrix Rolf A. T. M. van Benthem Gijsbertus de With 《Advanced functional materials》2014,24(36):5745-5752
Superhydrophobic surfaces have been extensively investigated for self‐cleaning, low‐adhesion, anti‐corrosion or reduced‐drag applications. Roughness and its characteristics, i.e., morphology, overall roughness and individual feature size, is an essential factor for superhydrophobicity. Several experimental methods and theoretical models strived to predict how the surface wettability is affected by the surface roughness. However, due to the difficulty of making practical surfaces with well‐defined roughness profiles, only limited and arbitrary experimental studies focused on practical superhydrophobic films. Here, the roughness factors which determine the wetting properties of films are reported, based on monolayers of well‐defined raspberry silica‐silica nanoparticles, exhibiting a wide‐range and systematic variation of individual features sizes and ratios (large over small features). The advancing water contact angle does not depend on the feature size or ratio, while the contact angle hysteresis (CAH) is strongly dependent on both. The minimum size and size ratio to reach superhydrophobicity were determined. These new insights into the wetting of rough surfaces can be used to direct the design of practical superhydrophobic materials for advanced applications such as solar panels, microelectronics or microfluidic devices. 相似文献
12.
《Microelectronic Engineering》2007,84(5-8):945-948
The individual steps in fabrication of templates for UV-NIL processes are described. After spin coating a conductive copolymer (ESPACER 300) on top of the resist, insulating substrates have been structured by use of electron beam lithography at 20 keV beam energy. A three-dimensional (3D) pattern has been created in a low contrast positive tone resist PMMA 35k. By RIE in a CHF3 – O2 – process, the pattern has been transferred into the quartz substrate. Finally, the 3D structures have been replicated in a UV-NIL process. 相似文献
13.
以苯甲醚为溶剂,采用旋涂法制备PMMA(聚甲基丙烯酸甲酯)转移层膜。当PMMA的质量分数为5%、旋涂速度为2000~6000r/min时,转移层膜的厚度为90~150nm,粗糙度为0.3nm,可满足纳米压印要求。采用接触角测量仪测试计算出PMMA、PS转移层膜的表面能,并通过转移层膜与压印胶之间的粘附功和界面张力的计算,评价了PMMA、PS和Si片对压印胶的润湿和粘附性能。结果表明,PMMA膜可改善压印胶在基片上的润湿铺展性能和粘附性能,而PS膜虽能改善基片的润湿铺展性能,却不利于压印胶的粘附。 相似文献
14.
Hierarchical roughness makes superhydrophobic states stable 总被引:1,自引:0,他引:1
Nosonovsky Michael 《Microelectronic Engineering》2007,84(3):382-386
Roughness enhances hydrophobicity of a solid surface leading to high contact angles with water. To achieve low contact angle hysteresis along with a high contact angle, superhydrophobic surfaces should form composite interface (CI) with air pockets in the valleys between asperities. The CI is often unstable and can be irreversibly transformed into the homogeneous interface. We formulate stability criterion, identify mechanisms, which lead to destabilization of the CI, and show that these mechanisms are scale-dependent. To effectively resist these scale-dependent mechanisms, a multiscale (hierarchical) roughness is required. Such multiscale roughness is found in natural and artificial superhydrophobic surfaces. 相似文献
15.
The periodic arrays of nanostructure were successfully patterned on Si wafers by ultraviolet nanoimprint lithography (UV-NIL) using nanosphere lithography (NSL). Two-dimensional (2D) well ordered self-assembled arrays were obtained on Si wafer by using nanosphere and the tilted-drain method. We tried to combine two techniques and hard mold of Si mold for NIL and polymer mold of acrylate-based polymer were fabricated by NSL. The Si master mold and polymer mold were formed by Cr lift-off and ICP-RIE process. The surface has a low surface energy at the interface with 1H, 1H, 2H, 2H-perfluorooctyl-trichlorosilane (FOTS) vapor-coating, which can eliminate the problem of the adherence to the surface of the mold during demolding. Finally, nanopatterns were formed by UV-NIL, where the residual layer was not observed. 相似文献
16.
To solve the problems with coronary stent implantation, coronary artery stent surface was directly modified by three-beam laser interference lithography through imitating the water-repellent surface of lotus leaf, and uniform micro-nano structures with the controllable period were fabricated. The morphological properties and contact angle (CA) of the microstructure were measured by scanning electron microscope (SEM) and CA system. The water repellency of stent was also evaluated by the contact and then separation between the water drop and the stent. The results show that the close-packed concave structure with the period of about 12 μm can be fabricated on the stent surface with special parameters (incident angle of 3°, laser energy density of 2.2 J?cm-2 and exposure time of 80 s) by using the three-beam laser at 1 064 nm, and the structure has good water repellency with CA of 120°. 相似文献
17.
Superhydrophobic surfaces of dynamic stability are crucial for applications in water‐repellent materials. In this work, a hierarchical structure composed of a dendritic microporous surface with nanostructured porosity is demonstrated that shows robust superhydrophobicity with dynamic stability. The hierarchical structures are obtained on both copper foils and wires by a dynamic gas‐bubble template‐assisted electrochemical deposition method. The substrates can then be modified with alkyl thiols to obtain the surface superhydrophobicity. A new kind of testing, mechanical monitor‐assisted continuous water surface strokes, is developed to reveal the dynamic stability of the as‐prepared superhydrophobic copper wires. The as‐prepared superhydrophobic copper wires can exert a high propulsive force, and particularly, show little adhesive force in the process of continuous strokes on the water surface, exhibiting robust superhydrophobicity with dynamic stability. The approach allows a strategy for the fabrication of superhydrophobic surfaces with dynamic stability, and suggests a new method to evaluate the dynamic stability of superhydrophobic surfaces. 相似文献
18.
C. Auner U. Palfinger H. Gold J. Kraxner A. Haase T. Haber M. Sezen W. Grogger G. Jakopic J.R. Krenn G. Leising B. Stadlober 《Organic Electronics》2009,10(8):1466-1472
In this study we report on an innovative nanoimprint process for the fabrication of entirely patterned submicron OTFTs in a bottom-gate configuration. The method is based on UV-Nanoimprint Lithography (UV-NIL) combined with a novel imprint resist whose outstanding chemical and physical properties are responsible for the excellent results in structure transfer. In combination with a pretreated stamp the UV-curable resist enables residue-free imprinting thus making etching obsolete. A subsequent lift-off can be done with water. The UV-NIL process implies no extra temperature budget, is time saving due to short curing times, eco-friendly due to a water-based lift-off, simple because it is etch-free and completely r2r compatible. It works perfectly even if ultra-thin organic and hybrid films are used as gate dielectrics. On this basis entirely patterned functional submicron OTFTs with pentacene as the semiconductor are fabricated showing clear saturation, low switch-on voltage (~3 V) and a sufficiently high on–off ratio (103). 相似文献
19.
Sandra Gilles Matthias Meier Michael Prömpers Andre van der Hart Carsten Kügeler Andreas Offenhäusser Dirk Mayer 《Microelectronic Engineering》2009,86(4-6):661-664
Transparent polymers are considered as alternative low-cost mold materials in UV nanoimprint lithography (UV-NIL). Here, we demonstrate a nanoimprint process with molds made of rigid polymers novel for this application. These polymer molds are found to show high performance in the patterning with UV-NIL. Sub-50 nm structures were fabricated with this process. 相似文献
20.
AlGaN/GaN high electron mobility transistors(HEMTs)with high performance were fabricated and characterized.A variety of techniques were used to improve device performance,such as AlN interlayer,silicon nitride passivation,high aspect ratio T-shaped gate,low resistance ohmic contact and short drain-source distance. DC and RF performances of as-fabricated HEMTs were characterized by utilizing a semiconductor characterization system and a vector network analyzer,respectively.As-fabricated devices exhibited a maximum drain current density of 1.41 A/mm and a maximum peak extrinsic transconductance of 317 mS/mm.The obtained current density is larger than those reported in the literature to date,implemented with a domestic wafer and processes.Furthermore, a unity current gain cut-off frequency of 74.3 GHz and a maximum oscillation frequency of 112.4 GHz were obtained on a device with an 80 nm gate length. 相似文献