光刻机的演变及今后发展趋势

微电子技术的发展一直是光刻设备和技术发展与变革的动力。通过介绍光刻机的演变和所面临的挑战，揭示下一代光刻设备的发展潜力，结合比较极紫外光刻机和电子束曝光机的开发现状和特点，预言将来以极紫外光刻机、电子束曝光机和某种常规光刻机结合，来实现工业需要的各种图形的制备。     

掩模材料与新颖的衬底方案关键问题及新的良机

通过对掩模衬底材料和掩模加工工艺利用硬性分界条件可满足45nm及以下技术节点的掩模要求。此外类似于折射指数、平整度、成分、均匀性和应力等衬底材料的固有特性严重地影响到掩模加工性能和光刻性能。评述了45nm及以下技术节点对空白材料,掩模及晶片层面的要求。指出了对于关键问题及出现的问题的可仿效实施的方法,最后研究了集成用于高效光掩模工厂的掩模材料的实际情况分析。     

Physical Vapor Deposition of Molecular Glass Photoresists: A New Route to Chemically Amplified Patterning

A negative tone photoresist film, consisting of a molecular glass, a photoacid generator, and an acid labile crosslinker, was prepared by physical vapor deposition, a solvent‐free process. Subsequent to deposition, the coevaporated monomers were exposed using 365 nm radiation, subjected to a post exposure bake step, and developed in aqueous base to produce sub‐micron patterns. Combinatorial techniques were used to aid optimization of the photoresist by systematic variations in composition and exposure dose. Development factors such as concentration and time were also optimized.     

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.     

向商业化迈进的极紫外(EUV)光刻技术

在介绍EUV光刻原理和EUV光源基本概念的基础上,讨论了目前研究得最多、技术最成熟的激光产生的等离子体LPP光源,着重对EUV光源的初步应用和EUV光刻设备的开发进展情况进行了详细介绍与讨论。目前的研究进展表明,随着激光产生的等离子体EUV光源（LPP）功率的不断提高和EUV光刻设备的逐步成熟,极紫外（EUV）光刻技术将在2012年步入半导体产业的商业化生产。     

硅片调焦调平测量系统测试平台

硅片调焦调平测量系统测试平台用于对光刻机硅片调焦调平测量系统的性能进行检测。该平台模拟硅片调焦调平测量系统在光刻机中的测量对象的运动和工作环境,由三自由度运动台吸附硅片模拟光刻机工件台的垂向运动,采用比较激光干涉仪和硅片调焦调平测量系统同时对硅片测量的结果作为其性能的评估依据。该平台测量精确可靠,可以用于精度、分辨率和重复性等性能指标的检测。     

光学光刻的极限

讨论了光学光刻技术的各种分辨力增强技术(RETs),根据各类光刻设备的开发进展,探讨了光学光刻技术的加工极限。     

ASML扫描机与NIKON步进机的匹配技术

如何实现PAS扫描机与NSR步进机混合匹配,从匹配的可行性、匹配步骤、匹配精度控制、匹配校准问题进行分析,最终实现PAS5500/700与NSR2205i12之间的匹配和混合光刻技术,包括:(1)PAS扫描机与NSR步进机系统的匹配目的;(2)PAS扫描机与NSR步进机系统的匹配步骤;(3)PAS扫描机与NSR步进机系统的匹配参数调整;(4)PAS扫描机与NSR步进机系统的匹配校准;(5)PAS扫描机与NSR步进机系统的匹配试验过程及结果;(6)PAS扫描机与NSR步进机系统的匹配结论。该技术已成功地应用于高性能集成电路器件的研制和生产,实现了180 nm线宽和350 nm线宽工艺的稳定匹配曝光。     

Exposure parameters for MeV proton beam writing on SU-8

Proton beam writing was performed on a lithographic resist to determine the main parameters required to achieve the minimum feature size, maximum pattern lateral density and maximum aspect ratio. A 2.5 MeV proton beam focused to sizes between 1.5 and 2.5 μm was used to expose SU-8 negative resist. The number of protons per pixel was varied in the exposure of SU-8 with thicknesses between 5 and 95 μm. Patterns consisting of single pixels, single-pixel lines and multi-pixel areas with different densities were fabricated. The smallest structures achieved were posts 1.5 μm in diameter with 4:1 structure-space ratio in 15 μm thick resist and the highest aspect ratio structures of 20:1 in 40 μm resist were produced. It was found that the minimum feature size depended only on the beam size, and ±10% post size accuracy could be achieved within 40-70% variation of the number of protons. MeV proton beam allows a direct fabrication of complex shapes without a mask in single-step irradiation and, in addition, no proximity correction is needed. We present examples of MeV proton beam written single and multi-pixel microstructures with easily reproducible high aspect ratios and densities.     

Pattern‐Transfer Fidelity in Soft Lithography: The Role of Pattern Density and Aspect Ratio

Using high‐aspect‐ratio nanostructures fabricated via two‐photon laser‐scanning lithography, we examine the deformation of elastomeric stamps used in soft nanolithography and the fidelity of patterns and replicas made using these stamps. Two‐photon laser‐scanning lithography enables us to systematically regulate the aspect ratio and pattern density of the nanostructures by varying laser‐scanning parameters such as the intensity of the laser beam, the scanning speed, the focal depth inside the resist, and the scanning‐line spacing. Two commercially available stamp/mold materials with different moduli have been investigated. We find that the pattern‐transfer fidelity is strongly affected by the pattern density. In addition, we demonstrate that true three‐dimensional structures can be successfully replicated because of the flexible nature of elastomeric poly(dimethylsiloxane).