MMI微压印模板的设计与研究

微纳米压印技术作为代替传统光刻的一种新兴技术,有着重要的应用潜力。近年来在直接加工微器件如微流体、微生物器件,特别是在微平面光学器件方面得到了较快的发展。采用微压印法直接加工聚合物微平面光学器件是一个具有实用价值和研究价值的课题。该文首先讨论并选取了聚甲基丙稀酸甲酯(PMMA),研究了聚合物多模干涉(MMI)耦合器器件的微压印模板的设计和加工,讨论了压印模板材料的影响。根据典型基于MMI聚合物分光器件模板的设计实例,由聚合物的光学性能和分光要求,设计出模板的几何尺寸,通过微细加工工艺加工出模板,并给出了初步的热压印实验结果。     

纳米岛光刻技术及其应用

介绍了一种基于微加工技术的新方法——纳米岛光刻技术。利用该技术制造出几十纳米到微米尺度的岛结构，然后利用剥离、刻蚀等微加工技术，将该岛转化成纳米孔、纳米岛、纳米井等结构。该技术的特点是能够制造出具有各种密度的纳米结构(最高覆盖率可达50％以上)，且开发成本低，工艺性能优越，是一种有效制造纳米岛结构的专业方法。     

Micro and nano structures of carbonised polymer through pyrolytic transformation from polymer structures

Micro and nano structures of carbonised polymers resulting from the pyrolytic transformation of polymer structures are presented. Polymers have become increasingly popular as materials for micro/nano electromechanical systems (MEMS/NEMS), especially for chemical or biological application. Focus is on the transformation of polymer structures into carbonised structures using a pyrolysis process. Combination of this pyrolysis process with conventional MEMS/NEMS fabrication technology could provide various fine structures of carbonised polymer. Carbonised polymers have advantages over conventional carbon materials, with respect to compatibility with MEMS, because they can be transformed directly from a polymer structure. Three-dimensional micro and nano free-standing structures of carbonised polymer as typical MEMS/NEMS structures are reported. Micro molding process is used to demonstrate a unique polymer structure to be pyrolysed. Furthermore, EB lithography technology is employed for the patterning of polymers in addition to UV photolithography which is used by previous researches. A 100 nm wide bridge structure is designed as nano structures. In addition, the presented structures of carbonised polymer are expected to be applied to micro and nano functional devices such as electrochemical sensors by making the best use of their carbon-like features     

Shear-mode PMN-PT piezoelectric single crystal resonator for microfluidic applications

We report on the integration of a PMN-PT single crystal-based piezoelectric resonator in a microfluidic system. In this experiment, the resonator was implanted in the microfluidic channel through a standard soft lithography process with its top electrode in contact with the flowing fluid. The results showed that, activated in shear mode, the resonator sensed changes occurring along the fluid-electrode interface and gave responses in the form of impedance resonance frequency shift. By measuring the frequency shift, changes in the fluidic property (e.g. viscosity) could be monitored. Examples are given to demonstrate the potential use of the system for cell detections.     

Fabrication of a 3D stamp with the micro- and nano-scale patterns through combined NIL and optical lithography processes

Nanoimprint lithography is in the spotlight of the nano technology field for its ability to produce large area patterning [1], [2], [4]. This kind of lithography is also able to fabricate three-dimensional functional structures all at once. In order to fabricate three-dimensional structures for an entire wafer, simple fabrication of three-dimensional large area stamp that combines micro- and nano-scale patterns is required. This paper proposes, the fabrication process of three-dimensional large area stamp that incorporates both micro- and nano-scale pattern. The three-dimensional stamp, which accounts for areas that range from 70nm to 3um, is fabricated on a Si substrate using nanoimprint lithography and optical lithography.     

石墨烯微纳结构加工技术的研究进展

简单介绍了石墨烯独特的光电子性质,说明实现其在光电子器件中应用的有效方法是进行微纳加工。接下来对主要的石墨烯微纳加工技术——掩膜光刻、转移压印以及激光直写和干涉进行详细阐述,通过实例对每种加工技术的关键步骤和特点进行说明,并分析比较了不同加工技术的优缺点。然后对近期出现的转移压印辅助光刻和飞秒直写辅助转移压印技术的加工流程进行详细介绍,阐述将两种加工技术相结合应用于石墨烯微纳结构加工的优势。最后,简单展望了石墨烯微纳加工未来的发展趋势,指出需进一步研究的问题,对如何更好地实现石墨烯微纳结构的加工提出一些建议。     

Nanofabrication of gallium nitride photonic crystal light-emitting diodes

We describe a comparison of nanofabrication technologies for the fabrication of 2D photonic crystal structures on GaN/InGaN blue LEDs. Such devices exhibit enhanced brightness and the possibility of controlling the angular emission profile of emitted light. This paper describes three nano lithography techniques for patterning photonic crystal structures on the emitting faces of LEDs: direct-write electron beam lithography, hard stamp nanoimprint lithography and soft-stamp nanoimprint lithography with disposable embossing masters. In each case we describe variations on the technique as well as its advantages and disadvantages. Complete process details have been given for all three techniques. In addition, we show how high performance GaN dry etch techniques, coupled with optical process monitoring can transfer resist patterns into underlying GaN material with high fidelity.     

The fabrication of three-dimensional nano-structures by defocused electron beam energy

We demonstrate a novel method to fabricate three-dimensional structure with various shapes using defocused electron beam lithography (DEBL) for optical elements. In this study, we experimentally analyzed the relationship between the shape profiles of exposed patterns and defocusing length by varying parameters for e-beam lithography.Through these experiments, we found out that the shape profiles of exposed patterns depended on the defocusing length at the specific conditions in the e-beam lithography. This is due to the fact that the distribution and intensity of electron beam energy are changed by the defocusing length degree in the DEBL. These results allow the fabrication of three-dimensional (3D) structures with various shapes for optical elements by varying the defocusing length under the proper conditions of e-beam lithography. Based on these results, we can fabricate the 3D patterns with hemispherical shape for nano lens array and nano cone shape for SERS (surface enhanced Raman spectroscopy) and optical diffraction grating patterns with nano scale depth and width.     

纳米压印技术

传统光学光刻技术的高成本促使科学家去开发新的非光学方法,以取代集成电路工厂目前所用的工艺.另外,微机电系统(MEMS)的成功启发科学家借用MEMS中的相关技术,将其使用到纳米科技中去,这是得到纳米结构的一种有效途经.纳米压印在过去的几年里受到了高度重视,因为它成功地证明了它有成本低、分辨率高的潜力.纳米压印技术主要包括热压印、紫外压印(含步进-闪光压印)和微接触印刷等.本文详细讨论纳米压印材料的制备及常用的三种工艺的工艺步骤和它们各自的优缺点.并对这三种工艺进行了比较.最后列举了一些典型应用,如微镜、金属氧化物半导体场效应管、光栅等.     

电子束纳米光刻技术研究

纳米光刻技术在微电子制作中起着关键作用 ,而电子束光刻在纳米光刻技术制作中是最好的方法之一。我们使用VB5电子束曝光系统 ,经过工艺研究 ,现已研究出最细分辨率剥离金属条为 17nm ,最小剥离电极间距为 10nm ,最细T型栅为 10 0nm。     

高能电子束曝光技术研究

介绍了将商用透射电镜JEM—2000EX改造为高能电子束曝光系统的研制工作，在现阶段研制工作的基础上进行了曝光实验。结果表明，利用此高能电子束曝光系统可以制备出纳米线条，并且能够制备出具有高深宽比的微细结构，从而为微小器件的加工提供了新的方法。     

Fabrication of roll imprint stamp for continuous UV roll imprinting process

Recently, nano imprint lithography has been developed for mass production of nano-scale patterns on large-scale substrates. To achieve high throughput and cost reduction, roll-to-roll imprint lithography has been introduced. The roll-to-roll imprint is the suitable process for large area patterning, especially, flexible substrates for display devices. In this study, roll-to-roll imprint stamp is fabricated using poly-vinyl alcohol (PVA) mold and UV curable poly-dimethylsiloxanes (PDMS) resin for continuous roll imprinting process. The PVA mold was chosen since it is flexible and can be dissolved in water. Since the PDMS can form thin SiO_x layer on the surface by oxygen plasma treatment, silane based hydrophobic anti-stiction layer can be formed directly on the surface of PDMS. As a result, nano-sized patterns were successfully formed on the flexible PET films by UV roll imprinting with the fabricated roll stamp.     

Anti‐reflection and hydrophobic characteristics of M‐PDMS based moth‐eye nano‐patterns on protection glass of photovoltaic systems

To maximize the incident light, moth‐eye nano‐patterns were formed on a glass plate that was used as the protection glass for photovoltaic systems. These moth‐eye nano‐patterns were formed using a nano‐imprint lithography process and increased the transmittance of the glass plate by minimizing the reflection of light at the surface. After the formation of the moth‐eye nano‐patterns, the surface was coated with a trichloro‐silane based self‐assembled monolayer in order to create a hydrophobic surface because the hydrophobic surface induced a self‐cleaning effect. The transmittance of the glass plate increased from 91 to 94% at wavelength of 500 nm after the moth‐eye structure was introduced. Thus, the short circuit current (J_SC) of the I–V characteristics and the charged capacity of the photovoltaic system increased up to 6% after replacing the conventional protection glass with the moth‐eye nano‐patterned glass. The durability of the moth‐eye nano‐patterns was evaluated with respect to an acidic environment, high temperatures and UV irradiation. From these evaluation results, the values of the transmittance and contact angle did not decrease after the nano‐patterns were soaked in sulfuric acid solutions with a pH of 2.0 for 48 h, exposed to a temperature of 120°C for 48 h, and irradiated 10 times with UV light for 4 h. Copyright © 2010 John Wiley & Sons, Ltd.     

Third dimension of proximity effect correction (PEC)

New nano applications, like T-gates, bridges, mirror arrays, blazed gratings, 3D zone plates, 3D holograms and MEMS devices require highly accurate 3D patterning of resist.De facto, Electron-beam (EB) lithography is a process for high resolution patterning in lateral dimensions. The aforementioned 3D applications, imply accurate control of resist thickness, after development, thus critically depending on proximity effect corrections (PEC) in the third dimension. We show a feasibility test for a new 3D PEC approach, using Layout BEAMER e-beam lithography software.     

在图像传感器和存储产品中应用硅通孔工艺的300mm光刻与键合技术

三维集成的技术优势正在延伸到大量销售的诸如消费类电子设备潜在应用的产品领域。这些新技术也在推进着当前许多生产工艺的包封能力,其中包括光刻工艺和晶圆键合。〉还需要涂胶．形成图形和刻蚀图形结构。研究了一些用于三维封装的光刻和晶圆键合技术问题并将叙述全部的挑战和适用的解决方案。技术方面的处理结果将通过晶圆键合和光刻工序一起讨论。     

激光光刻技术的研究与发展

光刻技术作为制备半导体器件的关键技术之一将制约着半导体行业的发展和半导体器件的性能。随着半导体工业的发展,集成电路的特征尺寸越来越小,光刻技术将面临新的挑战。分析了激光光刻技术,包括投影式光刻和激光无掩膜光刻技术的研究现状,着重介绍了极紫外光刻(EUVL)作为下一代光刻技术的发展前景和技术难点、激光无掩膜光刻技术的发展,特别是激光近场扫描光刻、激光干涉光刻、激光非线性光刻等新技术的最新进展及其在高分辨率纳米加工领域的应用前景。     

Boehmite filled hybrid sol-gel system as directly writable hard etching mask for pattern transfer

We discuss some preliminary results on the development of a new kind of positive tone resist whose peculiarity is an extreme dry etch resistance. This profitable property is obtained by loading and compatibilizing with ceramic nano particles a radiation sensitive sol-gel silica based hybrid organic/inorganic system. With an appropriate choice of the nano particles, the investigated approach is suitable to be adapted and optimized for achieving high selectivity in plasma etching processes of different materials. Here, we specifically demonstrate how the filling with boehmite nano particles (aluminum hydroxide, y-AlO(OH)) confers a much higher selectivity (>60) to the radiation sensitive silica based system when used for the etching of silicon, that show a selectivity <2 if unloaded. The patterning of the new resist was carried out by X-ray lithography while the dry etching tests were made with a fluorine-based chemistry.     

Tensile tests of micro anchors anodically bonded between Pyrex glass and aluminum thin film coated on silicon wafer

Micro anchor is a kind of typical structures in micro/nano electromechanical systems (MEMS/NEMS), and it can be made by anodic bonding process, with thin films of metal or alloy as an intermediate layer. At the relative low temperature and voltage, specimens with actually sized micro anchor structures were anodically bonded using Pyrex 7740 glass and patterned crystalline silicon chips coated with aluminum thin film with a thickness comprised between 50 nm and 230 nm. To evaluate the bonding quality, tensile pulling tests have been finished with newly designed flexible fixtures for these specimens. The experimental results exhibit that the bonding tensile strength increases with the bonding temperature and voltage, but it decreases with the increase of the thickness of Al intermediate layer. This kind of thickness effect of the intermediate layer was not mentioned in the literature on anodic bonding.     

应用传统紫外光刻机进行紫外压印

基于紫外光固化的紫外纳米压印技术可在常温常压条件下实现纳米结构批量复制,具有高分辨率、高效率和低成本的优点。通过对紫外纳米压印原理和工艺的分析,制备了石英玻璃模板,实现了在商用紫外固化聚合物OG154上的紫外纳米压印,转移复制了具有100nm特征的5cm×5cm面积的纳米结构图形。同时,介绍了如何利用传统紫外光刻机的套刻对准系统进行紫外纳米压印和套刻对准的方法。     

Simulation tool design for the two-axis nano stage of lithography systems

For advanced electron beam lithography systems, a simulation tool for a two-axis nano stage is developed in this paper. The stage is equipped with piezo-actuators and flexure guides. Even if piezo-actuators are believed to be feasible for realizing nano scale motions, it is difficult to predict their characteristics due to their nonlinearities such as hysteresis and creep. In this paper, the nonlinear properties are modeled considering the input conditions. In detail, the hysteresis is described as a first order differential equation with 24 sets of the hysteresis parameters and the creep is modeled as a time-dependent logarithmic function with two sets of creep parameters. The characteristics of the flexure guides are analyzed using the finite element method and are embodied into a multi-body-dynamics simulation tool. The dynamic behavior of the simulation tool is compared with the experimental data.