严格电磁场波导方法的三维厚胶光刻工艺仿真（英文）

无论是在微机电系统(MEMS)还是集成电路(IC)领域,SU-8厚胶光刻已经成为制造高深宽比结构的主流工艺。为了取代昂贵而耗时的光刻实验,一套能够良好预测显影形貌,从而为优化光刻制造提供有效帮助的光刻仿真软件就成为必要而有价值的工具。基于严格电磁场波导法的理论,给出一种针对SU-8光刻胶在紫外光下的三维光刻仿真模型。利用该模型,能很好地预测显影后的光刻胶内光强分布和立体形貌。并完成了一系列仿真和实验结果来验证模型的有效性。仿真结果给出横截面光强分布图和显影立体形貌模拟图形,并与相应的实验结果进行对照。结果验证了本文提出的仿真模型的正确性,并且表明三维混合模型在保证精确性的前提下,较之其他仿真算法运算速度更快。     

基于严格电磁场模型的光学光刻仿真（英文）

光学光刻技术已广泛应用于微电子机械系统(MEMS)以及集成电路(IC)领域。由于光刻工艺设备的价格十分昂贵,因此利用光刻仿真这一技术来预期工艺结果并优化工艺中存在的问题就显得很有必要。研究了一种基于严格电磁场模型的求解方法——波导方法,并将此方法拓展应用于模拟MEMS领域中的厚胶曝光场景。通过这一模型,可以模拟光刻胶内部的光强分布,并进一步预测出显影后的光刻胶形貌。最后,针对某些特定掩模版结构,给出它们的仿真结果并验证其正确性。     

基于严格电磁场模型的光学光刻仿真

光学光刻技术已广泛应用于微电子机械系统（MEMS）以及集成电路（IC）领域。由于光刻工艺设备的价格十分昂贵,因此利用光刻仿真这一技术来预期工艺结果并优化工艺中存在的问题就显得很有必要。研究了一种基于严格电磁场模型的求解方法波导方法,并将此方法拓展应用于模拟MEMS领域中的厚胶曝光场景。通过这一模型,可以模拟光刻胶内部的光强分布,并进一步预测出显影后的光刻胶形貌。最后,针对某些特定掩模版结构,给出它们的仿真结果并验证其正确性。     

信息光学 光学记录、存储与器件

TP333.2 2006032252母盘刻录中信息符成形模拟与实验研究=Si mulation andexperi ment study on recording maskin mastering[刊,中]/宋洁(清华大学光盘国家工程研究中心.北京(100084)) ,陈垦…∥光电子·激光.—2006 ,17(3) .—265-268介绍了光刻胶的性能和反应机理,建立了光刻模型,讨论了曝光和显影对信息符的综合影响并对信息符形貌进行了仿真,着重分析刻录激光光斑能量分布对不同周期记录符的影响。以Shipley AZ-1350光刻胶和相应的显影液以及DVD母盘的生产为例,验证了仿真的正确性。图5参7(杨妹清)TP333.4 2006032253多阶光存储研…     

SU-8光刻胶应变分布光学全场检测方法

由于SU-8光刻胶的内应力将会影响高深宽比结构的全金属光栅的制作质量,本文针对近年来SU-8光刻胶应力测量困难的情况,提出了一种基于激光剪切散斑干涉技术的SU-8光刻胶应变分布测量的新方法。该方法通过对被测胶体加载前后两幅干涉图像的处理,直接得到被测胶体结构的全场应变分布情况,由胶体的应变变形数据即可反映出内应力的变化和分布趋势。同时使用ANSYS有限元分析软件对同一被测胶体进行应变仿真模拟研究,获得胶体结构的变形场仿真数据。组建了实验系统,进行了实验验证,结果表明:实际测量变形量约为1.189μm,仿真的最大变形量为1.088μm,测量误差在允许范围内,且测量的形变趋势与仿真模拟结果相一致,表明激光剪切散斑干涉技术可应用于SU-8光刻胶的应变分布全场无损检测。     

BSRF上同步辐射深度光刻的实验研究

大结构深度和高深宽比是同步辐射深度光刻的突出优点.提出采用现有掩模,进行多次曝光、显影的方法,实验获得厚2.2mm的胶结构.系列研究掩模、光刻胶、基底、光谱和光强对深宽比的影响,实验获得深宽比104的胶结构.     

BSRF上同步辐射浓度光刻的实验研究

大结构深度和高深宽比是同步辐射深度光刻的突出优点。提出采用现有掩模，进行多次曝光、显影的方法，实验获得厚2.2mm的胶结构。系列研究掩模、光刻胶、基底、光谱和光强对深宽比的影响，实验获得深宽比104的胶结构。     

基于光刻胶三维形貌的光刻多参数联合优化方法

多参数联合优化是光刻分辨率增强技术的发展方向。提出了一种以光刻胶三维形貌差异为评价目标的光刻多参数联合优化方法。以多个深度位置的光刻胶图形误差为目标函数,对光源、掩模、投影物镜波前、离焦量和曝光剂量进行联合优化,提高了光刻胶图形三维形貌的质量。为获得较高的优化效率,采用自适应差分进化算法实现光源和掩模的优化,并针对其他参数的特点,采用不同优化方法进行优化。对密集线、含有交叉门的复杂掩模图形和静态随机存储器中的典型图形进行了仿真验证,可用焦深的最大值分别达到237nm、115nm和144.8nm,曝光宽容度的最大值分别达到18.5%、12.4%和16.4%。与基于空间像的光源掩模投影物镜联合优化技术相比,所提方法明显扩大了工艺窗口。     

入射光束角度及强度偏差对多光束干涉光刻结果的影响

建立了多光束干涉光刻干涉场内光强分布的数学模型,仿真计算了双光束、三光束、四光束干涉曝光情况下,入射光束存在角度偏差以及各入射光强不同时的干涉图样,并与理想状态的模拟结果进行对比.结果表明:光束入射角度偏差主要影响干涉图样的形状和周期;入射光的光强不同是降低图形对比度的主要因素.利用402nm波长激光光源进行多光束干涉光刻实验.设定激光器输出功率32mW,每两束光夹角为16°,通过控制曝光、显影工艺,双光束干涉光刻产生周期为1.4μm的光栅、点阵和孔阵结构,三光束干涉光刻产生周期为1.7μm的六边形图形阵列.该模型可为利用干涉光刻技术制备微细周期结构,提高光刻图形质量,提供一定的理论参考.     

基于单幅图像的集成电路引脚共面性检测方法

集成电路(IC)芯片引脚的共面性检测是确保其贴装质量的关键。基于单幅图像提出一种IC引脚共面性检测方法。首先,基于单目视觉系统建立相机、光源和被测表面的关系模型;其次,给出发光二极管(LED)环形结构光源的光强标定方法,并通过实验确定被测IC引脚材质的相关参数;然后,基于建立的光强与图像灰度的关系模型给出高度信息的求解方法;最后,基于高度信息还原IC引脚及其焊点的表面三维形貌。实验结果表明,本文方法检测IC芯片引脚及其焊点的实验结果与实际测量结果相比,其高度测量误差小于±0.08 mm,相对误差为-2.6%,验证了本文方法的有效性。     

Simulation of 3D inclined/rotated UV lithography and its application to microneedles

A 3D model is set up to simulate the exposure process of inclined/rotated UV lithography for negative SU-8 resists. The formation of inclined resist pillars and microstructures with truncated cone shapes is simulated based on a 3D exposure model in combination with a post exposure bake model for chemically amplified resists and the Mack development model. As one of the interesting applications employing this promising lithography technique for MEMS fabrication, a solid microneedle for drug delivery is simulated.     

A novel design and micro-fabrication for copper (Cu) electroforming bipolar plates

A novel design and micro-fabrication were developed for micro-proton exchange membrane (PEM) fuel cell stack bipolar plates with cross section of 5 cm² and thickness of about 650 μm. Copper metals were used to make bipolar plates (BPs) by using a LIGA-like micro-fabrication process of deep UV lithography in order to obtain SU-8 resist patterns/and SU-8 mould. Through two-sided exposure and development, copper metal bipolar plates with serpentine (meandering) flow field configurations for a micro PEM fuel cell stack, were fabricated and performance tests through polarization characteristics were conducted; this made it possible for the first time to consider copper sheets as suitable for BPs in micro PEM fuel cell stacks.     

355nm激光曝光SU-8胶的XPS谱和FT-IR谱研究

SU-8光胶因具有良好的光刻性能,并可获得稳定的高深宽比而在微加工领域得到了广泛的应用。众多研究采用不同的光源对其进行了多种光刻研究,本文应用355nm激光对SU-8胶进行曝光,分别采用XPS谱和FT-IR谱分析了SU-8胶与激光相互作用过程中,355nm激光对SU-8胶的作用以及反应前后主要成分含量、分子结构的变化,初步探讨了SU-8胶中激光曝光能量与透入深度的关系。     

Experimental test of high-resolution process modelling in electron beam lithography at 25 to 50 keV

Summary An additive process using the three-level resist scheme for X-ray mask fabrication by electron beam lithography is analysed by Monte Carlo simulation of electron scattering. The resist exposure is calculated for specific e-beam test patterns aimed at 0.2μm resolution. The time evolution of the developed resist profiles is simulated by using a string model for dissolution. Relevant process variables such as e-beam energy (25 to 50 keV) and resist thickness are investigated. Simulation results demonstrate that 50 keV is altogether a preferred condition, compared to 25 keV, leading however to different pattern transfer techniques, according to resist thickness. The process modelling is compared with previously reported experimental results. Good qualitative agreement is found, indicating that modelling can be used as an effective aid in the quantitative evaluation of the process. Supported by Finalized Project MA.D.E.S.S of Consiglio Nazionale delle Ricerche.     

基于NOA73微球与SU-8微柱的微探针制作

集成紫外固化胶NOA73微球与SU-8微柱制造的亚毫米探针,可以作为关键部件应用于三坐标测量机。NOA73微球通过NOA73对其他溶液的界面张力形成,柱子由深紫外光穿过微球曝光SU-8形成。这种新技术利用甘油补偿NOA73与空气折射率差,使得紫外光透过NOA73微球后保持接近平行。最终得到高深宽比的探针结构,高度超过1 200 m,微柱侧壁与基底呈89。     

SU-8 based planar metamaterials with fourfold symmetry as selective terahertz absorbers

We report on the absorption properties of polarization-insensitive transmissive and reflective metamaterial absorbers based on two planar aluminium periodic structures and SU-8 epoxy resist. These absorbers were investigated using numerical simulation and experimental methods in the terahertz range (below 2 THz). SU-8 is a very promising organic material for dielectric layers in planar metamaterials, because its application simplifies the process of fabricating these structures and significantly reduces the fabrication time. The experimental absorption of the metamaterial absorbers has narrowband characteristics that were consistent with the numerical simulations. Power flow analysis in the transmissive metamaterial unit cell shows that the absorption in the terahertz range occurs primarily in the SU-8 layer of the absorber.     

Characterisation of PMMA microfluidic channels and devices fabricated by hot embossing and sealed by direct bonding

In this study we fabricated a silicon-based stamp with various microchannel arrays, and demonstrated successful replication of the stamp micro-structure on poly methyl methacrylate (PMMA) substrates. We used maskless UV lithography for the production of the micro-structured stamp. Thermal imprint lithography was used to fabricate microfeatured fluidic platforms on PMMA substrates, as well as to bond PMMA lids on the fluidic platforms. The microfeature in the silicon-based (silicon wafer coated with SU-8) stamp includes microchannel arrays of approximately 30 μm in depth and 5 mm in width. We produced various channels without pillars, as well as with SU-8 pillars in the range of 50–100 μm wide and 6 μm in height. PMMA discs of 1 mm thickness were utilized as the molding substrate. We found 10 kN applied force and 100 °C embossing temperature were optimum for transferring the micro-structure to the PMMA substrate.     

Multibeam X-ray lithography to form deep regular microstructures

A method for the fabrication of regular microstructures with a high aspect ratio (for example, X-ray gratings) by direct multibeam vector recording in layers of an SU-8 resist is presented. An X-ray beam with a wavelength from 0.4 to 1.7 Å is used for recording. The features of the method are described. The fabricated samples of regular microstructures of the SU-8 resist and gold-plated X-ray masks are presented as finished products.     

Application of Huygens-Fresnel diffraction principle for high aspect ratio SU-8 micro-/nanotip array

A high-aspect-ratio (approximately 30) SU-8 micro-/nanotip array whose shape is defined by diffraction was fabricated by a single UV photolithography procedure and its exposed dose control. The fabrication result of the tip agrees well with the Rayleigh-Sommerfeld solution of the Huygens-Fresnel principle at wide observation distances. In a near field below distance 2 microm (only several times of wavelength), necking points also agree with the solution, although it is assumed that the distance is much larger than wavelength. It can be also applied to control the shape of the tip and to determine the critical dose D(c) of SU-8 and other photocurable polymers.     

压印光刻中紫外光诱导阻蚀胶固化控制计算

针对压印过程中两类基本的复型缺陷，从实验分析中得出其主要原因是曝光后阻蚀胶的固化程度难以控制．通过分析紫外曝光光源与阻蚀胶的光谱匹配性，得出使得阻蚀胶固化的有效波长为365nm；对光诱导紫外曝光过程中紫外光的传播分析，建立了阻蚀胶中光强分布的数学模型；用粘度来表征阻蚀胶的固化程度，建立了阻蚀胶中的粘度分布函数．分析了阻蚀胶对365nm紫外光的吸收率以及膜厚对阻蚀胶中光强分布均匀性的影响，得出复型后阻蚀胶凸起处的光强分布均匀性对吸收率及膜厚更为敏感的结论．