低空频模板实现微光变图像的激光直写方法

提出一种采用低空频模板实现微光变图像(micro-optical variable device)的激光直写方法。低空频模版由6×6个不同取向线条状单元图形构成，单元图形由空间光调制器输入，经精缩投影光学系统缩微，在光刻胶面上逐单元曝光。控制单元图形的结构取向能够实现各种复杂设计和特性的微光变图像。在低频光栅模板的基础上，给出了定向散斑结构输入模板的设计方法，它可进一步改进图像的非彩色效果。采用自行研制的SVG-LDW04型激光直写系统制作了微光变图像，其结构特征线度为4μm～100μm。该方法无需机械旋转机构，为实现微光变图像提供了一种便捷有效的手段。     

手机导光板熔合微光学阵列研究

为了研究手机侧发光背光模组,理论分析并模拟了在导光板表面直接熔合微光学结构的手机背光系统.结果表明,熔合微光学结构后,手机背光系统的出射光场发生变化,使得部分光线在偏离视场中心55°的方向上会聚,为设计新型集成手机微光学导光板奠定基础.     

微纳金属光学结构制备技术及应用

微纳光学结构制备技术一直是微纳光子学器件发展的技术瓶颈.针对微纳光学结构制备技术向小尺寸、高精度和广泛应用发展的趋势,报道了基于电子束、X射线和接近式光学的混合光刻制作微纳金属光学结构技术.针对微纳光子学器件复杂图形开发了微光刻数据处理体系,基于矢量扫描电子束光刻设备在自支撑薄膜上进行1×高分辨率图形形成,利用X射线光...     

导光板底面熔合微棱镜出射亮度规律研究

基于导光板底面直接熔合微棱镜取代目前背光系统平面反射膜和网点两层结构,推导了棱镜底角和出射亮度方向角之间的关系,提出导光板出射亮度方向角与棱镜远近光源底角的解析公式.用LightTools软件对导光板进行建模仿真,通过改变棱镜两个底角,得到出射亮度峰值方向和底角之间的变化规律.理论值与模拟仿真值基本符合,为背光模组一体化的研究提供理论和实验依据.依据上述规律,设计出一体化导光板结构,其中,微棱镜近光源角为86°,远光源角为37°,亮度达到现行3M背光系统指标.     

高分辨率衍射图形的DMD并行激光干涉直写

通过将数字微反射镜（Digital Micro-mirror Device,DMD）输入阵列图形微缩干涉成像,激光干涉直写系统在光刻胶板上得到缩小的干涉光斑图形,像素特征尺寸3.5 μm,干涉条纹周期1 μm.控制刻蚀深度、干涉条纹取向和DMD输入图形的结构,系统能数字化完成2D/3D、3D光变图像、超微图形文字以及二元光学元件的制作,实现了超高分辨率图形与高效的干涉光刻.给出了实验结果.     

手机侧背光照明导光板设计模拟

 为了提高手机侧背光照明导光板的亮度及亮度均匀性,对上表面为41 mm×26 mm的楔形导光板进行了模拟仿真,并对导光板底面不同的印刷式散射网点排布、不同的楔形导光板底面角度及不同的球缺形凸包网点排布进行了研究。结果显示,导光板底面排布印刷式散射网点时,导光板上表面亮度分布的均匀性较差,而出射光通量的百分比小于26%;当导光板底面排布球缺形凸包网点时,导光板上表面亮度分布的均匀性得到提高,出射光通量的百分比提高10%。楔形导光板底面角度81°时的出光效果优于85°时的效果。     

导光板散射网点的布局与出光均匀性的研究

从背光模组的基本结构出发,通过理论分析确定了影响导光板散射网点排布的公式,证明了散射网点的排布规律对背光模组出光均匀度有影响。对一款背光模组商品建立了简化模型,通过光学软件TracePro模拟分析以及实验验证,证明了背光模组商品的出光均匀度还有提升的可能性。在此基础上,又重点分析了散射网点行间距的变化值,散射网点直径和散射网点初始行间距对导光板出光均匀度的影响。经过反复仿真模拟,取得了一组参数值,可以使优化后的导光板出光均匀度比背光模组商品的出光均匀度好。研究的结论可作为导光板散射网点设计的参考,对背光模组的设计具有指导意义。     

一种圆环LED侧入式背光模组设计

侧入式背光板能有效地减少显示背光模组的厚度和背光所需的LED光源数目,为获得均匀照度的侧入背光模组,介绍一种圆环侧入式导光板结构。推导导光板中网点的设计规律,得到圆环侧入式导光板的网点大小的分布函数。利用VBA语言编程在CAD中生成网点分布,结合软件模拟分析,验证了导光板显示区域中光照亮度均匀性达到90％以上,满足了侧入式背光模组中圆环形导光板工程设计上的要求。     

消除数字光刻像素栅格衍射影响的研究

提出用优化成像系统设计参量的方法有效消除基于数字微镜阵列的栅格结构及其衍射对微结构成像质量的影响.模拟结果表明,当照明光源的波长为0.365 μm,系统的数值孔径为0.3左右,缩小倍率为10～20×时,栅格像的可见度在0.1以下,DMD的栅格结构对成像质量的影响大幅降低;对微透镜的成像分析发现,合理的成像系统结构参量能有效地减少栅格的影响.如果结合DMD显示图形的可编程特点,优化图形的结构或灰度,则能在像面获得较理想的曝光量分布,达到快速加工二维和三维微结构的目的.实验结果证实了优化系统参量可有效消除DMD栅格的影响.     

具有存储功能的衍射图像光刻系统的研制

研制了一种在衍射光变图像器件上进行信息存储的新型数字化激光光刻系统。采用空间光调制器作图形自动输入,双远心投影成像系统在光刻记录面上缩微图形。通过光栅干涉光学头对记录面上的微图形进行干涉调制,使微图形上产生干涉条纹,条纹空间频率范围为500-1200lp／mm。在光刻胶干版上的存储实验表明,在衍射光变图像上的单角度存储信息密度大于3．7Mbit／cm^2。改变干涉条纹取向、条纹间隔和需要存储的图形,光刻系统可实现信息的旋转复用存储。上述光刻系统将会在防伪和衍射光变图像器件制造领域有良好应用。     

Fabrication of dual brightness enhancement structures on light guide plates using UV roll-to-plate imprinting lithography

We proposed a roll-to-plate UV imprinting lithography (RPIL) process for fabricating dual brightness enhancement structures on light guide plates (LGPs). The refractive indices of the UV resin for layers imprinted on the LGP were investigated through computer-aid optical analysis and experiments. The refractive indices of the resins ranged from 1.49 to 1.69, and flat films such as polyethylene terephthalate (PET) films used by the media layer have better on-axis luminous intensity enhancement rate rates. Using the proposed process, several vertical prismatic structures on the LGP achieved a formability rate of 97% respectively, and the luminous intensity enhancement rate exceeded 2.1, which is almost the same as that of 3M's dual-prism film. This study demonstrates the potential of our proposed process for fabricating multi-layer of microstructures on the LGP.     

Rapid fabrication of surface-relief plastic diffusers by ultrasonic embossing

This paper discusses an innovative and effective ultrasonic embossing process, which enables the rapid fabrication of surface-relief plastic diffusers. The metallic mold bearing the microstructures is fabricated using a tungsten carbide turning machine. A 1500-W ultrasonic vibrator with an output frequency of 20 kHz was used to replicate the microstructure onto 1-mm-thick PMMA plates in the experiments. During ultrasonic embossing, the ultrasonic energy is converted into heat through intermolecular friction at the master mold/plastic plate interface due to asperities to melt the thermoplastic at the interface and thereby to replicate the microstructure. Under the proper processing conditions, high-performance plastic diffusers have been successfully fabricated. The cycle time required to successfully fabricate a diffuser is less than 2 s. The experimental results suggest that ultrasonic embossing could provide an effective way of fabricating high-performance plastic diffusers with a high throughput.     

用于数字光刻的非对称式投影物镜设计

针对DMD数字光刻,利用ZEMAX光学设计软件,设计出了一套适用于型号 0.7XGA DMD的10片式光刻投影物镜。该物镜采用非对称性结构,前组为改进的三分离物镜,后组为匹兹伐物镜加平像场镜,分辨率为2 m,近轴放大倍率为-0.15,像方数值孔径NA为0.158,全视场波像差小于/20 ,畸变小于0.014%,焦深为20 m,通过各项评价可知系统已经达到了衍射极限。在对该镜头进行公差分析后,利用Monte Carlo方法,模拟组装加工了100组镜头,得到90%的镜头MTF＞0.46,50%的镜头MTF＞0.51,证明了这种非对称性结构加工和校装的可能性。     

Replication of microchannel structures in polymers using laser fabricated glass–ceramic stamp

A new microreplication process with photo-etchable glass–ceramic stamps and polymers is presented. This process has two main advantages: a rapid master fabrication with a laser process and a flexible replication process compared with conventional nano- or microreplication technique on polymers. Photo-etchable glass–ceramics are used for the master stamp. Micropatterns can be rapidly transferred with a laser direct writing process and the removal of the glass–ceramics can be efficiently achieved with a wet etching process. Therefore, microstructures with flat bottom surfaces and straight sidewall structures can be obtained, which is difficult in the laser direct writing process. A microstamping process of applying heat and pressure, also referred to as hot embossing lithography or microstamping, can replicate microstructures on polymer surfaces. In this work, the fabricated glass–ceramic stamps are used for the replication process and various replicated polymer microstructures are presented.     

Replicated data-matrix array generators

The fabrication and replication of binary spot array generators using 4 and 16 levels gratings is investigated. The elements are designed using iterative Fourier transform algorithm and fabricated by electron-beam lithography. Finally elements are copied by fabricating nickel shims and using hot embossing technique. In each step the optical signals are measured and signals are characterized using bit error rate as a measure of quality. The results show that although 16 level element gives theoretically superior performance, the bit error rate is much lower (∼0.2%) for replicated 4 level elements than for their 16 level counterparts (∼9%).     

激光光刻中数字微镜器件关键技术研究

在无掩模激光光刻系统中,TI(Texa instrument,德州仪器)公司基于DLP(digital light processing,数字光处理)架构的DMD(digital micromirror device,数字微镜器件)系统已经得到应用,但是存在光刻图像质量和光刻速度无法提高等瓶颈.提出采用单片FPGA控制...     

Pixel-based partially coherent image method for maskless lithography system

Maskless lithography (ML) provides a fast and low-cost method for projecting the images of IC or micro features onto photoresist. However, it needs an efficient simulation method to evaluate the performance of lithography process. In this paper, a pixel-based partially coherent image method for digital micro-mirror device (DMD) based ML is proposed based on the linear invariant theory. In our method, the mask is sampled by DMD pixel (each pixel corresponding to each micro-mirror) and expressed by rect function. Using the shift theory of Fourier transform and the stacked pupil operator approach, we build a matrix Φ for system response function of rect function. If the DMD pixel state matrix is S, then the aerial image can be calculated with two matrix multiplication I(x,y) = SΦ.     

Fabrication of multi-scale structures with multiple X-ray masks and synchrotron hard X-ray irradiations

Synchrotron hard X-ray irradiation can be utilized in lithography processes to manufacture precise structures. Due to the difficulty of precise X-ray mask fabrication in hard X-ray lithography, this X-ray process has been used mainly to fabricate precise microstructures. In this study, a technology is proposed for fabricating novel multi-scale patterns that include submicron-scale structures using hard X-rays. The required X-ray masks for submicron-sized patterning are fabricated by a simple UV lithography process and sidewall metal deposition. Above all, thanks to the high penetration capability of hard X-rays with sub-nanometer wavelengths, it is possible to employ multiple masks to fabricate a variety of patterns. By combining each sub-micron X-ray mask with typical micro-sized X-ray masks, a unique X-ray lithography is performed, and various multi-scale structures are fabricated. The usefulness of the proposed technology is demonstrated by the realization of these structures.     

Surface micro-texturing of metallic cylindrical surface with proximity rolling-exposure lithography and electrochemical micromachining

In this paper, a new method is developed for fabricating large-scale three-dimensional (3D) microstructures for cylindrical objects with proximity rolling-exposure lithography (PREL) and electrochemical micromachining (EMM). This method is capable of patterning a wide variety of shapes, including shapes that are impossible to fashion with conventional methods over a large area. A cylindrical rod covered with photoresist is subarea-exposed with a collimated ultraviolet source through a mask by rotating the rod through a definite angle to expose each area. To ensure the shape accuracy of the microstructures, a 2D exposure model is built to predict and optimise such parameters as the rod radius, exposure angle and effective light intensity. The experimental results show that the ideal exposure time for a cylindrical layer is three to four times longer than that for a planar layer with the same thickness. The relative errors of the microstructures decrease as the exposure angle decreases or as the microstructures increase in size. Furthermore, EMM is extended to non-planar surfaces and ordered microstructures with feature sizes down to 40 μm are obtained over large areas on the cylinder.     

Profile calculation of gold nanostructures by dispersed-nanosphere lithography through oblique etching for LSPR applications

Nanosphere lithography is an inexpensive method used to fabricate gold nanostructures on a substrate. Using dispersed-nanosphere lithography, in which the nanospheres are dispersed on a substrate, 2D or 3D nanostructures can be fabricated by obliquely depositing a gold film on the nanospheres and etching the gold film afterward. These nanostructures are tunable and acute, and are thus good emitting elements for the localized surface plasmon resonance applications. So far, for the fabrication of nanostructures on a substrate with dispersed nanospheres, only 2D nanostructures have been reported through perpendicular etching. We report in this paper that the 3D nanostructures fabricated by dispersed-nanosphere lithography are rigid non-conformal structures, and perpendicular gold etching can be expanded to oblique etching, which provides more possibilities for fabricating the gold nanostructures in various shapes. The profiles of gold nanostructures after several varying angle depositions, and their final profiles after perpendicular or oblique etching, are calculated in this paper. Our profile simulations are applicable for nanospheres (or microspheres) within the range of tens of nanometers to tens of micrometers, and are consistent with our fabricated nanostructures observed using scanning electron and atomic force microscopy. Electronic Supplementary Material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.