GaAs表面处理与可靠性

本文采用不同表面处理方法制备样品，利用Ｃ－Ｖ和边栅效应测试图形研究其对肖特基势垒的正向ｎ值，反向击穿电压和边栅效应的影响。将不同表面处理方法制备的器件进行可靠性试验，由此给出ＧａＡｓ表面处理的优化方法。     

转印技术及其应用

压敏转印技术是一种新型制图技术,主要在印制电路板上供制作字符和名牌等用。使用时,只要在转印片基背后图形处稍加摩压力,即能将符号转印到被粘物体上,故使用方便、灵活、效率高,质量可靠稳定,图面美观,富有立体感,成本低,且可任意组合。     

一种改进的几何约束分枝定界SLAM重定位算法

重定位技术是机器人在已有SLAM地图的环境中依靠自身传感器重新获得定位信息的关键技术。几何约束分枝定界重定位(GCBB)算法是一种有效的方法,但是其存在计算速度慢的缺点。针对GCBB算法的不足,从两个方面对其进行改进:一是采用分组方式进行数据关联;二是结合传感器探测范围在局部区域中选择特征进行数据关联。仿真结果表明,所提出的快速几何约束分枝定界重定位(FGCBB)算法能够正确实现重定位,且计算复杂度与观测数目两者之间服从线性关系,当处理观测数目较多的问题时,FGCBB的计算效率明显优于GCBB算法。     

大尺寸高分辨率AM OLED的激光热转印技术

激光热转印(Laser Induced'rhermal Imaging,LITI)是1种新型全彩色AM oLED像素图形制造技术.LITI技术有很多独特的优点,如转印的薄膜厚度均匀,具有多层薄膜叠加转印能力,分辨率高以及易于在大尺寸基板上生产等.韩国三星SDI研究开发中心的研究人员研发并优化了LITI技术制备小分子OLED的各项工艺.所制得的器件具有优异的稳定性.采用LITI技术制造的2.0"QVGA OLED显示器在150 cd/m2白光亮度下,工作寿命超过了20 000 h.研究人员还建立了1条基于第4代基板的LITI OLED中试生产线,为大规模生产LITI OLED做先导研究.     

用于亚微米图形加工的离轴照明技术

本文主要介绍了国外用于提高光学片子步进机成像性能的高分辨率、大焦深的离轴照明技术。通过几种照明技术的比较，指出了可用于亚半微米器件图形转印的环形照明技术在未来６４Ｍ～２５６ＭＤＲＡＭ器件时代进行规模生产的潜力所在。     

基于半导体工艺制备碳纳米管阴极图形阵列

提出一种成本低、简单易行的碳纳米管图形阵列制备技术。首先在硅基底上采用热解工艺生长碳纳米管(CNT)阴极,再用光刻腐蚀法制备阴极图形阵列。研究了掩模精度及腐蚀液的浓度对图形阵列的影响,对所得到的图形样品进行XPS分析表明,图形腐蚀彻底、图形边沿轮廓清晰;以二极管结构FED测试场发射性能知:该阴极开启场1.5V/μm;在电场强度为2.0V/μm下,电流密度为58mA/mm2,发光亮度高达450cd/m2。     

基于基站定位和GPS的双定位跟踪系统架构和实现

本文介绍了实现基于基站定位即移动位置服务(LBS——Location Based Service)和GPS双重定位系统的实现方案,前端通过普通ARM单片机进行控制,将实时坐标信息和异常信息通过GPRS网络发至后台,后台解析后可对目标物进行跟踪定位及处理。本文采用的定位技术有两种,一     

光学CT方法用于大坝垂线坐标的检测

把光学ＣＴ技术应用于大坝变形垂线坐标的测量，研制了用阵列光源和电荷耦合器件ＣＣＤ线阵构成的一种新型垂线坐标仪。工程现场测试资料表明，该坐标仅用观测精度高，稳定可靠并能自动化监测的优点。     

一种计算有耗媒质中跨界目标电磁散射的高效算法

为了克服传统离散复镜像法计算有耗媒质中索莫菲尔德积分的不足,提出了一种基于增强离散复镜像法的插值算法。当场点和源点位于分界面两侧时,谱域格林函数中同时包含场点和源点位置坐标,传统二级离散复镜像法无法一次拟合复指数参数,考虑将谱域核函数对场点坐标分离,然后建立复镜像参数随源点坐标的一维插值表,从而可以对复镜像参数进行插值运算;当场点和源点均位于有耗媒质中时,二级离散复镜像法的采样路径会带来错误,提出对谱域核函数进行形式变换再进行求解,从而使插值法适合有耗媒质中格林函数的计算;为了扩大传统二级离散复镜像法的横向计算距离,在对复镜像参数进行复指数级数拟合时,选择增强离散复镜像法的采样路径。该方法同传统对格林函数进行插值的方法相比,在计算复杂度降低的同时,效率和精度都获得了大大提高。     

超微粉末的扫描电镜观察法

扫描电镜分辨率高，景深大，放大倍数连续可变，可应用扫描电镜对小直径粉末样品的超微结构、几何尺寸进行观测。用扫描电镜观察超微粉末样品涉及：试样制备技术，观察时工作条件的选择等两个方面。     

Replication of an UV-NIL stamp using DLC coating

We fabricated a stamp for UV nanoimprint lithography using a diamond-like carbon (DLC) coating on polyvinyl alcohol (PVA), which is commonly used in water-soluble polymer replica stamps. The RF-PECVD method was used to deposit a DLC on the PVA replica. An optical adhesive was then used to affix a glass plate to the DLC-coated PVA replica as a backup material, and the PVA replica was dissolved in water from the DLC layer stuck to the glass plate. The same topology was applied to successfully replicate the master stamp with sub-1 μm features. The correlation between the dimensions of the master stamp’s features and the corresponding replicated features was excellent. When replicating stamps, the properties of DLC yield the benefits of both good mechanical properties and low surface energy.     

一种新型聚合物微透镜阵列的制造技术

提出了一种利用软模压印制备微透镜阵列的技术.采用传统的光刻胶热熔方法制备微透镜阵列母板,利用复制模具的方法在聚二甲基硅氧烷(PDMS)上得到一个和母板表面图形相反的模具,最后通过压印的方法把PDMS模具上的图形转移到涂有紫外固化胶的玻璃基片上,待紫外胶完全固化后可得到和母板一致的微透镜阵列.经过测试微透镜阵列的焦点图像和表面形貌可发现最后制备的微透镜阵列表面形貌均匀、聚焦性能良好、光忖强均匀.     

硅油稀释PDMS法制备紫外纳米压印软模板

软模板的制作是紫外纳米压印中关键的技术,模版的分辨率直接决定了压印图形的最小分辨率。使用具有高度均匀、100nm级孔洞阵列结构的多孔氧化铝作为母版,使用基于液态浇铸的硅油稀释聚二甲基硅氧烷(硅油和聚二甲基硅氧烷的质量比为1:2)法制备出具有规则点阵结构的软模板。通过SEM和AFM表征发现,特征图形得到了有效转移,特征尺度保持在100nm左右。相对于传统的模板制备方法,此方法成本低、流程简单、适合大规模生产,是一种非常有前途的软模板制备方法。     

Large area nanosize array stamp for UV-based nanoimprint lithography fabricated by size reduction process

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.     

Fabrication of high aspect ratio nanostructures on 3D surfaces

A combination of different materials and processes was used to create high aspect ratio nanostructures on 3D surfaces. The high aspect ratio structures were formed on thermoplastic foils using UV-Nanoimprintlithography (UV-NIL) with a poly (dimethylsiloxane) (PDMS) stamp which was fabricated by soft lithography. An epoxy mixture with a higher glass transition temperature than the thermoplastic foil was used as a resist for UV-NIL. The hydrophobicity of structured substrates was characterized by the surface contact angle. Substrates with an additional chemical treatment were also produced and characterized. Results of contact angle measurement showed that superhydrophobic surface properties can be obtained with structured and chemically treated samples. The foils were further used as a substrate in a thermoforming process to transfer the structures into a microchannel. Using this process, 3D structured foils can be fabricated with high accuracy. The foils were used as a master structure for a replica molding process which allowed the fabrication of 3D structured polymer parts. With the presented method, microchannels with superhydrophobic surface properties can be fabricated.     

软印刷技术

软印刷技术是基于弹性体印章/模具来转移图形结构的微纳加工技术。详细介绍了软印刷技术中转移图形结构的多种方式,并探讨软印刷技术在微纳电子学、光学、传感器、生物等领域的广泛应用。对软印刷技术的弹性体印章/模具制备、聚二甲基硅氧烷的属性、理论研究等进行了探讨。     

A versatile pattern inversion process based on thermal and soft UV nanoimprint lithography techniques

Si master molds are generally patterned by electron-beam lithography (EBL) that is known to be a time-consuming nanopatterning technique. Thus, developing mold duplication process based on high throughput technique such as nanoimprint lithography can be helpful in reducing its fabrication time and cost. Moreover, it could be of interest to get inverted patterns (holes instead of pillars) without changing the master EBL process. In this paper, we propose a two step process based on thermal nanoimprint lithography (T-NIL) (step 1) and soft UV assisted nanoimprint lithography (UV-NIL) (step 2) to invert a master EBL mold. After the two inversion steps, the grand-daughter Si mold exhibits the same pattern polarity as the EBL mold. For step 1, pattern transfer using ion beam etching (IBE) of a thin metallic underlayer is the critical step for dimension control due to the low NXR1020 resistance. For step 2, the optimized reactive ion etching (RIE) step allows transfer with good anisotropy even for nanostructures at the 50 nm-scale. For structures larger than 100 nm, this inversion process has been successfully applied to large field replication (up to 1.5 cm²) on whole wafer.     

Nanoelectrode lithography using a flat mold with a pattern defined by different conductivities

Nanoelectrode lithography is a pattern duplication method that combines nanoimprint with an electrochemical reaction. The method can form an oxide pattern directly on a semiconductor or metal. This method can use flat molds with patterns defined by substances with different conductivities, while the conventional nanoimprint technique must use a mold with a relief pattern. In this paper, the mold pattern for the technique is defined with an oxide material on the surface of a conductive substrate. Nanoelectrode lithography itself can be used to form a flat mold by using a conductive mold with a relief pattern, which leaves an oxide pattern via the anodic oxidation of Si. AFM lithography also can utilize an electrochemical reaction in the air to generate an oxide pattern on a conductive substrate, which gives us a flat mold. This paper shows that both types of flat mold can transfer a pattern to a target substrate. These strategies will allow us to realize on-demand mold fabrication, mold modification, and an easy way of obtaining a mold with a finer pattern.     

Fabrication of 50 nm patterned nickel stamp with hot embossing and electroforming process

Fabrication of imprint stamp is a key issue of nanoimprint lithography. In this study, we attempt to fabricate the nickel imprint stamp using hot embossing lithography and electroforming processes. As small as 50 nm sized patterns of original silicon master were faithfully transferred to polyvinyl chloride (PVC) film. By electroforming on hot embossed PVC film, nickel stamp, which has the same patterns of original silicon master stamp, was successfully fabricated.     

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.