热压印刻蚀技术

纳米压印刻蚀技术是通过压模的方法实现纳米结构批量复制的。这一技术具有高分辨、高效率和低成本的优点。它与现行的光学刻蚀技术流程相似,具有较好的兼容性与继承性。详细介绍了热压印刻蚀技术的核心工艺步骤:压印模板的制备、热压印胶的选择、压模和撤模、反应离子刻蚀以及热压印过程中的聚合物流动机理,探讨了热压印刻蚀技术中的基础科学问题。还分析了纳米压印刻蚀技术的研究现状,展望了纳米压印刻蚀技术的应用前景。     

纳米压印光刻技术--下一代批量生产的光刻技术

纳米压印光刻技术已被证实是纳米尺寸大面积结构复制的最有前途的下一代技术之一。这种速度快、成本低的方法成为生物化学、μ级流化学、μ-TAS和通信器件制造以及纳米尺寸范围内广泛应用的一种日渐重要的方法,如生物医学、纳米流体学、纳米光学应用、数据存储等领域。由于标准光刻系统的波长限制、巨大的开发工作量、以及高昂的工艺和设备成本,纳米压印光刻技术可能成为主流IC产业中一种真正富有竞争性方法。对细小到亚10nm范围内的极小复制结构,纳米压印技术没有物理极限。从几种纳米压印光刻技术中选择两种前景广阔的方法——热压印光刻(HEL)和紫外压印光刻(UV-NIL)技术给予介绍。两种技术对各种各样的材料以及全部作图的衬底大批量生产提供了快速印制。重点介绍了HEL和UV-NIL两种技术的结果。全片压印尺寸达200mm直径,图形分辨力高,拓展到纳米尺寸范围。     

纳米压印光刻模版制作技术

在下一代光刻技术中,光刻的成本越来越高,这使得工业界开始寻找新的技术。纳米压印作为非光学的下一代光刻技术,具有分辨率高、成本低、产率高等诸多优点,因而可能应用于将来的半导体制造中。同时,纳米压印也可以用于微机电系统(MEMS)和其他纳米结构的图形复制。纳米压印光刻技术主要包括热压印、紫外固化压印和微接触法压印。介绍了在这3种纳米压印光刻技术中,压印模版制作的制作工艺和模版表面的防粘连处理,并且讨论3种压印方法适用的不同领域。     

DNA analysis by single molecule stretching in nanofluidic biochips

Stretching single DNA molecules by confinement in nanofluidic channels has attracted a great interest during the last few years as a DNA analysis tool. We have designed and fabricated a sealed micro/nanofluidic device for DNA stretching applications, based on the use of the high throughput NanoImprint Lithography (NIL) technology combined with a conventional anodic bonding of the silicon base and Pyrex cover. Using this chip, we have performed single molecule imaging on a bench-top fluorescent microscope system. Lambda phage DNA was used as a model sample to characterize the chip. Single molecules of λ-DNA stained with the fluorescent dye YOYO-1 were stretched in the nanochannel array and the experimental results were analysed to determine the extension factor of the DNA in the chip and the geometrical average of the nanochannel inner diameter. The determination of the extension ratio of the chip provides a method to determining DNA size. The results of this work prove that the developed fabrication process is a good alternative for the fabrication of single molecule DNA biochips and it allows developing a variety of innovative bio/chemical sensors based on single-molecule DNA sequencing devices.     

Direct Patterning of Metal Chalcogenide Semiconductor Materials

Lithography is one of the most widely used methods for cutting‐edge research and industrial applications, mainly owing to its ability to draw patterns in the micro and even nanoscale. However, the fabrication of semiconductor micro/nanostructures via conventional electron or optical lithography technologies often requires a time‐consuming multistep process and the use of expensive facilities. Herein, a low‐cost, high‐resolution, facile, and versatile direct patterning method based on metal–organic molecular precursors is reported. The ink‐based metal–organic precursors are found to operate as negative resists, with the material exposed by different methods (electron‐beam/laser/heat/ultraviolet (UV)) to render them insoluble in the development process. This technical process can deliver metal chalcogenide semiconductors with arbitrary 2D/3D patterns with sub‐50 nm resolution. Electron beam lithography, two‐photon absorption lithography, thermal scanning probe lithography, and UV photolithography are demonstrated for the direct patterning process. Different metal chalcogenide semiconductor nanodevices, such as photoconductive selenium‐doped Sb₂S₃ nanoribbons, p‐type PbS single‐nanowire field‐effect transistors, and p‐n junction CdS/Cu₂S nanowire solar cells, are fabricated by this method. This direct patterning technique is a versatile and simple micro/nanolithography technology with considerable potential for “lab‐on‐a‐chip” preparation of semiconductor devices.     

NIL—a low-cost and high-throughput MEMS fabrication method compatible with IC manufacturing technology

Current MEMS fabrication technology cannot satisfy the simultaneous needs of 3D structure fabrication and compatibility with IC manufacturing technology, which have impeded the development of MEMS industrialization to a certain extent. Nanoimprint lithography (NIL) provides a new MEMS fabrication method that is compatible with IC manufacturing technology and bears high throughput and low cost. This paper presents an in-house prototype NIL tool with a high precision automatic alignment system based on moiré fringe signals. Some printing results of nanostructures or micro-devices using the prototype are presented, and hot embossing lithography, one typical NIL technology is depicted in detail by taking microlens array fabrication as an example. High fidelity and fine uniformity demonstrate NIL will be a new method to fabricate 3D structures of MEMS.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

3D materials made of gold using Nanoimprint Lithography

In this work we show large area 3D stacking of gold structures like Split Ring Resonators (SRRs) and fishnet structures using Nanoimprint Lithography (NIL).Two main fabrication processes are used to stack multiple layers of such structures on top of each other: For the stacked fishnet structures a finished double-layer of gold structures is covered with a spacer layer which is planarized using chemical mechanical polishing so that a second layer can be processed on top. For the SRR structures a transfer printing process is used. Here the gold structures are transferred from one substrate onto another substrate. Especially this process is a new and unique possibility to stack gold patterns by transferring gold structures several time on the same substrate and therefore to build up 3D materials in a fast and cost efficient way.     

自适应光学技术在深层动态荧光显微成像中的应用和发展

荧光显微成像技术是开展微观生命科学研究的重要手段和工具,使用该技术可以观察生物体内的精细结构、动态追踪生物体内组织、细胞、细胞核、蛋白、小分子等不同尺度的生命活动过程。其中,研究深层组织高时空分辨率荧光显微成像技术,是当前成像领域一个前沿问题。应用自适应光学技术实时补偿经由不透明散射、非均匀生物组织传播而引入的复杂波前畸变已被证实是实现上述技术的一种有效途径。文中首先归纳了深层动态荧光显微成像的需求和特点,随后分别介绍了自适应光学技术近几年在共聚焦显微成像、随机光学重构显微成像、光激活定位显微成像、受激辐射光淬灭显微成像、双光子/多光子激发显微成像中的相关应用,并对今后的研究问题和发展方向提出展望。     

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.     

Controlling resist thickness and etch depth for fabrication of 3D structures in electron-beam grayscale lithography

In many applications such as optoelectronic devices, three-dimensional (3D) structures are required. Examples include photonic band gap (PBG) crystals, diffractive optical elements, blazed gratings, MEMS, NEMS, etc. It is known that the performance characteristics of such structures are highly sensitive to their dimensional fidelity. Therefore, it is essential to have a fabrication process by which such 3D structures can be realized with high dimensional accuracy. In this paper, practical methods to control thickness of the remaining resist and etch depth, which may be employed for fabrication of such 3D structures using grayscale electron-beam lithography, are described. Through experiments, explicit control of the remaining resist thickness and etch depth at the resolution of 20 nm for the feature sizes of 0.5 μm and 1 μm has been successfully demonstrated. Also, the 1:1 ratio of silicon to resist etching rates was achieved for transferring the remaining resist profile onto the silicon substrate.     

SiGeC薄膜表征对于光刻对准性能的影响研究

Si1-x-yGexCy是继Si和GaAs之后又一重要的半导体材料。由于Si1-x-yGexCy具有优于纯Si材料的良好特性,器件和制程又可与Si工艺兼容,采用Si1-x-yGexC及其Si1-x-yGexCy/Si异质结所制作出来的器件如异质结双极晶体管(Heterojunction Bipolar Transistor,HBT),其电性能几乎可达到GaAs等化合物半导体制作的同类器件的水平,而且在成本上低于GaAs HBT。因此Si1-x-yGexCy可能是未来微电子发展进程中必不可少、并起着关键作用的一种材料。文章对Si1-x-yGexCy薄膜的表征进行了探索,在总结大量数据的基础上,验证了利用Si1-x-yGexCy薄膜的反射率进行光学表征的方法的可行性。同时,文章系统研究了Si1-x-yGexCy薄膜的工艺条件、薄膜成份、薄膜厚度等参数对光刻对准性能的影响。     

用于聚合物基微流体MEMS的等离子体活性晶圆键合技术

Lab-on-chip或μ-TAS(micro-totalanalysissystems)结合流体处理、检测及数据分析,是一种便携式的低成本高效器件。在微流体应用中,聚合物具有比硅或玻璃器件更明显的优势,它包括:宽泛的材料选择性,成本低、效率高,使用任意性,生物兼容性,抗化学品和工艺灵活性。为了实现采用这类材料制备小型集成化系统,我们发展了新的制备与封装技术。这项工作着眼于运用等离子体活化低温直接键合技术实现纳/微结构聚合物在低温条件下进行封装。由纳米压印光刻制作的纳/微结构的聚合物器件,可能是异质(聚合物与玻璃或硅)或同质(聚合物与聚合物)键合。为了改进键合材料的物理和化学熔合,键合工序通常在接近聚合物的玻璃化转变温度的高温下进行。但遗憾的是,高温损伤了微细图形,特别是对于高深宽比结构。在EVG810LT 等离子体反应室里,我们采用软射频频率等离子体表面处理,来进行聚合物的等离子体活化,它能在不改变聚合物体特性的前提下清洗和活化聚合物顶层。最终结果是,在EVG501晶圆键合机上,两个活化的表面在低温下通过施加一个适中的、均匀的接触压力而连接在一起,保证了空腔密封并防止了小结构的破坏和变形。键合工艺条件为:真空条件为从大气到200~1000Pa、接触压力为2～5kN、温度从室温到80℃。RR     

Multiphoton Lithography as a Promising Tool for Biomedical Applications

Multiphoton lithography (MPL) is a powerful and useful structuring tool capable of generating 2D and 3D arbitrary micro- and nanometer features of various materials with high spatial resolution down to nm-scale. This technology has received tremendous interest in tissue engineering and medical device manufacturing, due to its ability to print sophisticated structures, which is difficult to achieve through traditional printing methods. Thorough consideration of two-photon photoinitiators (PIs) and photoreactive biomaterials is key to the fabrication of such complex 3D micro- and nanostructures. In the current review, different types of two-photon PIs are discussed for their use in biomedical applications. Next, an overview of biomaterials (both natural and synthetic polymers) along with their crosslinking mechanisms is provided. Finally, biomedical applications exploiting MPL are presented, including photocleaving and photopatterning strategies, biomedical devices, tissue engineering, organoids, organ-on-chip, and photodynamic therapy. This review offers a helicopter view on the use of MPL technology in the biomedical field and defines the necessary considerations toward selection or design of PIs and photoreactive biomaterials to serve a multitude of biomedical applications.     

Fabrication of Flexible Binary Amplitude Masks for Patterning on Highly Curved Surfaces

This paper describes soft lithography methods that expand current fabrication capabilities by enabling high‐throughput patterning on nonplanar substrates. These techniques exploit optically dense elastomeric mask elements embedded in a transparent poly(dimethylsiloxane) (PDMS) matrix by vacuum‐assisted microfluidic patterning, UV–ozone‐mediated irreversible sealing, and chemical etching. These protocols provide highly flexible photomasks exhibiting either positive‐ or negative‐image contrasts, which serve as amplitude masks for large‐area photolithographic patterning on a variety of curved (and planar) surfaces. When patterning on cylindrical surfaces, the developed masks do not experience significant pattern distortions. For substrates with 3D curvatures/geometries, however, the PDMS mask must undergo relatively large strains in order to make conformal contact. The new methods described in this report provide planar masks that can be patterned to compliantly compensate for both the displacements and distortions of features that result from stretching the mask to span the 3D geometry. To demonstrate this, a distortion‐corrected grid pattern mask was fabricated and used in conjunction with a homemade inflation device to pattern an electrode mesh on a glass hemisphere with predictable registration and distortion compensation. The showcased mask fabrication processes are compatible with a broad range of substrates, illustrating the potential for development of complex lithographic patterns for a variety of applications in the realm of curved electronics (i.e., synthetic retinal implants and curved LED arrays) and wide field‐of‐view optics.     

193nm光刻投影物镜单镜支撑仿真分析及实验研究

光刻是大规模集成电路制造过程中最为关键的工艺,光刻的分辨力主要取决于光刻投影物镜的光学性能。光刻投影物镜光学元件面形精度为纳米量级,其对光学元件的加工及物镜单镜支撑提出了极高的要求。为193nm光刻投影物镜高精度的单镜面形,设计了一种运动学单镜支撑结构。运用有限元法(FEM)分析光刻投影物镜单镜运动学支撑结构在重力下物镜镜片的面形变化量,经分析物镜镜片的峰值(PV)值为15.46nm,均方根(RMS)误差为3.62nm。为了验证有限元计算精度,建立了可去除参考面面形及被测面原始面形的方法。经过分析对比,仿真结果与实验结果面形的PV值为2.356nm,RMS误差为0.357nm。研究结果表明,所设计的基于运动学193nm光刻投影物镜单镜支撑结构能够满足193nm光刻投影物镜系统对于物镜机械支撑结构的要求。     

Triangular Elastomeric Stamps for Optical Applications: Near‐Field Phase Shift Photolithography, 3D Proximity Field Patterning,Embossed Antireflective Coatings,and SERS Sensing

The use of a decal transfer lithography technique to fabricate elastomeric stamps with triangular cross‐sections, specifically triangular prisms and cones, is described. These stamps are used in demonstrations for several prototypical optical applications, including the fabrication of multiheight 3D photoresist patterns with near zero‐width features using near‐field phase shift lithography, fabrication of periodic porous polymer structures by maskless proximity field nanopatterning, embossing thin‐film antireflection coatings for improved device performance, and efficient fabrication of substrates for surface‐enhanced Raman spectroscopic sensing. The applications illustrate the utility of the triangular poly(dimethylsiloxane) decals for a wide variety of optics‐centric applications, particularly those that exploit the ability of the designed geometries and materials combinations to manipulate light–matter interactions in a predictable and controllable manner.     

半导体光刻技术及设备的发展趋势

随着芯片集成度的不断提高、器件尺寸的不断缩小,光刻技术和光刻设备发生着显著变化。通过对目前国内外光刻设备生产厂商对下一代光刻技术的开发及目前已经应用到先进生产线上的光刻技术及设备进行了对比研究,对光刻技术和光刻设备的发展趋势进行了介绍,并对我国今后半导体光刻技术及设备的发展提出了合理化建议。     

Flexible Photonic Radiative Cooling Films: Fundamentals,Fabrication and Applications

Photonic structures designed at sub-wavelength scales have emerged as a promising avenue for various energy applications, including cooling devices, water harvesting, photovoltaics, and personal thermal management, which have significantly transformed the global energy landscape. Particularly, flexible photonic radiative cooling films, which facilitate heat dissipation from surfaces by emitting it into outer space via infrared radiation, have achieved great progress in recent years. In this review, the different approaches used to design photonic structures for manipulating solar reflectance and optimizing thermal emittance are summarized. On this basis, this review discusses advancements in flexible radiative cooling films that have been meticulously adhere to these design principles, alongside their cooling effects over recent years. Furthermore, a comprehensive overview of the progress is presented in the photonic integration with new functionality and the fabrication techniques of photonic structures. Lastly, this review highlights the remarkable potential of radiative coolers in various fields. In prospect, the widespread adoption of flexible photonic radiative cooling films holds immense promise for diverse applications.     

Evolution of T-shaped gate lithography for compound semiconductors field-effect transistors

T-shaped gate formation is a major processing step in the fabrication of high-performance FET-based III-V devices. Traditional bilayer or trilayer E-beam lithography methods using PMMA/(PMMA&PMAA) copolymers are high-cost options which also lack the required critical dimension control for manufacturing. Lithography methods that use only a single layer of PMMA for the formation of T-shaped gate stem, and routine I-line resist lithography for the tee-top, i.e., hybrid T-shaped gates, have been developed and extensively used in manufacturing. This approach has also been extended to the fabrication of deep submicron T-shaped gates using all I-line optical lithography. Both chemical shrinks and chromeless phase-shift resolution enhancement techniques have been investigated.