Tl_2O_3/聚-N-乙烯基咔唑复合纳米线的研究

微型化是纳米科技发展的关键驱动力之一，然而使用现行的光刻技术生产大规模集成电路器件的技术已经接近极限尺寸（～0．8μm）．1982年STM的研制成功使得在纳米尺寸上进行操作成为可能[1－3]同时，LB技术正在应用于纳米粒子薄膜的制备中[4]．进一步利用Iangmuir单层膜诱导控制     

嵌段共聚物的导向自组装

嵌段共聚物由于其在纳米尺度的自组装能力,通过在薄膜中的自组装可以得到特征尺寸小于10nm的周期性图形结构,近年来被广泛研究。导向自组装(Directed Self-Assembly,DSA)充分利用了嵌段共聚物在薄膜中进行自组装的优点,将"自下而上"的嵌段共聚物薄膜自组装技术和"自上而下"的光学光刻或电子束光刻等制备导向图形的技术结合起来。嵌段共聚物通过分子设计可得到层状、柱状、孔洞状等形貌多样的纳米结构。光刻模板表面的化学不均匀性使得嵌段共聚物和基底表面之间的相互作用可控,从而引导嵌段共聚物薄膜在一定的空间取向上定向排列。目前在导向自组装中常用的两种方法有直接在基底表面通过光刻制得前图形模板的制图外延法(几何控制)和基于对光刻模板表面进行化学修饰比如在模板表面接枝上一层中性层材料,从而通过化学诱导实现嵌段共聚物的定向自组装的化学外延法(化学控制)。导向自组装技术通过对微相结构的裁剪、表面修饰和尺寸控制,可以得到特征尺寸更小、密度更大、有序性更好的纳米图形,正逐渐成为最有前途的先进光刻技术方法之一。     

先进光刻材料

随着半导体产业的技术发展与进步,芯片制造在摩尔定律的推动下也在不断向先进工艺节点推进。与此同时,我们迫切需要开发与之相匹配的光刻材料来满足光刻图形化的快速发展需求。本文从光刻材料的成分和性能出发,介绍了光刻图形化技术所用的从紫外光刻胶、深紫外光刻胶、极紫外光胶、共轭聚合物光刻材料到导向自组装光刻材料,分析了光刻材料的发展现状,最后总结全文并对国内光刻材料的未来发展趋势进行展望。     

先进光刻技术：导向自组装

导向自组装(Directed Self-Assembly, DSA)光刻技术是一种极具发展潜力的新型图形化工艺,已被国际器件与系统路线图(International Roadmap for Devices and Systems, IRDS)列为下一代光刻技术的主要候选方案。DSA光刻技术是基于嵌段共聚物(Block Copolymer, BCP)自组装构建高分辨图案,能够突破传统光学光刻的衍射极限,具有高通量、低成本和延续性好等显著优势,已成为半导体工艺技术中的研发热点。将DSA与其它光刻技术如极紫外(Extreme Ultraviolet, EUV)光刻、深紫外(Deep Ultraviolet, DUV)光刻、紫外光刻和纳米压印光刻(Nanoimprint Lithography, NIL)等相结合,能极大地提高加工结构的分辨率以及器件的密度。目前,DSA光刻技术已被应用于鳍式场效应晶体管(Fin Field-Effect Transistor, FinFET)、存储器和光电子器件等领域,以期实现高密度集成和高效率低成本制造。本文对DSA光刻技术的原理、材料、工艺、应用以及在工业化进程中所面临的机遇和挑战进行全面的综述。     

PMMA基微流控芯片的准分子激光制备方法研究

采用准分子激光微加工技术在PMMA表面加工出了微混合器芯片.实验结果表明,采用准分子激光微加工技术可以加工出尺寸基本符合要求的、连续的、表面光洁度髙和边界整齐的微通道,可以加工出结构复杂的微流控芯片.     

扫描探针刻蚀技术可控构建牛血清白蛋白纳米结构

利用Dip-pen纳米刻蚀技术(简称DPN技术)在云母基底上构建出形状、尺寸可控的牛血清白蛋白(BSA)纳米结构.考察了针尖接触基底时间及针尖下行距离对构建的牛血清白蛋白纳米结构的影响.较长的针尖-基底接触时间及较深的下行距离可以沉积更多的牛血清白蛋白分子,构建牛血清白蛋白纳米结构的形状除了与墨水分子的本身性能有关,还与墨水-基底的相互作用有关.这些形状及尺寸可控的蛋白质纳米结构可以作为模板,进行金属、半导体等其它材料的组装,有望用于制造光电纳米器件及生物纳米器件.     

基于大气压下介质阻挡放电抑制LA-ICP-MS分析中元素分馏效应研究

采用自制的大气压下介质阻挡放电装置串联在激光剥蚀池与ICP炬管之间, 对激光剥蚀产生的气溶胶进行预电离. 结果表明, 元素瞬时信号轮廓的平滑度得以改善, 元素分析信号精密度(RSD, n=3)可提高2.55％. 在ArF准分子激光(193 nm)和Nd∶YAG 固体激光(213 nm)两种不同波长的激光剥蚀系统中, 元素分馏因子均比常规模式下更接近于1, 表明采用介质阻挡放电对气溶胶预电离后元素分馏效应得以有效抑制. 相比两种不同波长的激光剥蚀系统, 介质阻挡放电对213 nm固体激光的元素分馏效应改善作用明显.     

高分辨率极紫外光刻胶的研究进展

自集成电路芯片诞生半个多世纪以来,芯片尺寸在不断减少,以极紫外光刻为代表的光刻技术也有了显著的发展。同时,实现更高精度的光刻图案需要更加先进的光刻胶材料。传统的聚合物光刻胶材料因其相对分子质量大、高精度条纹易坍塌等缺陷使其使用受到限制。以分子玻璃和无机金属配合物光刻胶为代表的相对分子质量小、结构均一的新型光刻胶材料在国内外得到了广泛发展。本文对现阶段新型极紫外光刻胶材料的发展现状和趋势做了评述。     

先进光刻胶材料的研究进展

本文简述了光刻技术及光刻胶的发展过程,并对应用于193纳米光刻和下一代EUV光刻的光刻胶材料的研究进展进行了综述,特别对文献中EUV光刻胶材料的研发进行了较为详细的介绍,以期对我国先进光刻胶的研发工作有所帮助.     

双光子光聚合与功能微纳结构制备

随着纳米光电子学及生物医学组织工程领域的发展,器件的小型化、结构多样化及高度集成化,给微纳结构与器件制造领域带来了新的挑战。本文围绕飞秒激光双光子聚合技术,简要综述了双光子光聚合基本原理与双光子引发剂分子的研究进展,并对飞秒激光双光子聚合技术在功能微纳结构与器件制备中的应用及发展前景进行了展望。     

ArF激光光致抗蚀剂的研究进展

本文对近10年来有关ArF激光(193nm)光致抗蚀剂的研究开发情况进行了调研,对193nm光致抗蚀剂组成物的各个组分进行了归纳综述.从本文可以看出,利用193nm成像技术可以刻画线幅很细(<0.13μm)的图像,能适应信息技术的发展对于光致抗蚀剂高分辨率的要求.但若想将193nm成像技术在实践中推广应用,还有诸多问题需待研究解决.     

用于浸没式工艺的光刻胶研究进展

浸没式光刻技术是在原干法光刻的基础上采用高折射率浸没液体取代原来空气的空间,从而提高光刻分辨率的一种先进技术.此项技术的实际应用,为当前IC产业的飞速发展起到了关键的作用.本文概述了浸没式光刻技术的发展历程和浸没式光刻胶遇到的挑战及要求;对浸没式光刻胶主体树脂、光致产酸剂及添加剂的研究进展进行了综述;最后对浸没式光刻胶的研究发展方向作了进一步的探讨及初步预测.     

薄层软刻蚀法制备PMMA微图案结构

对现有的软刻蚀方法提出了改进,让其与压印技术及毛细力刻蚀技术相结合形成一种薄层软刻蚀技术,并以这种技术制备出PMMA薄膜微图案化结构.在30 mm/h的拉膜速度以及弹性印章表面图形深度确定不变的情况下,PMMA流体能够完全填充到弹性印章的微通道中,SEM和光学显微镜照片证明得到的PMMA微图案是相互分离的.因此,薄层软刻蚀技术可以克服普通微模塑方法制备分离图形困难和纳米压印技术中需要使用巨大机械压力的缺点.     

New fluoropolymer materials

We report the synthesis of two classes of fluoropolymers that could impact several key lithographic techniques; one has potential applications in next generation photolithography (193 nm, 157 nm, and immersion lithography) and the other in lithographic techniques which are emerging as viable alternatives to photolithography for future applications (i.e., soft lithography).     

On the iron oxide neutral cluster distribution in the gas phase. I. Detection through 193 nm multiphoton ionization

Iron oxide (FemOn) neutral clusters are generated in the gas phase through laser ablation of the metal and reaction with various concentrations of O2 in He. The mixture of expansion gas and neutral FemOn cluster species is expanded through a supersonic nozzle into a vacuum system, in which the clusters are ionized by an ArF excimer laser at 193 nm, and the ions are detected and identified in a time-of-flight mass spectrometer. In this report, the experimental parameters that influence the observed cluster distributions, such as ablation laser power, expansion pressure, vacuum system pressure, and 193 nm ArF ionization laser power, are explored. In the second paper in this series, the effect of the ionization laser wavelength (355 nm, 193 nm, 118 nm) on the observed cluster ion distribution is explored. The cluster ion distribution observed employing 193 nm laser ionization, is sensitive to the neutral cluster distribution as evidenced by the change in the observed time-of-flight mass spectra with changes in laser power, growth conditions, and expansion conditions. The thermodynamically stable neutral clusters for saturated O2 growth conditions are suggested to be of the forms FemOm, FemO(m+1), and FemO(m+2); which one of these series of neutral clusters is most stable depends on the size of the cluster. For m < 10, FemOm is the most stable neutral cluster series, for 10 < or = m < or = 20, FemO(m+1) is the most stable neutral cluster series, and for 21 < or = m < = 30, FemO(m+2) is the most stable neutral cluster series. Some neutral cluster fragmentation is clearly present for 193 nm ionization due to multiphoton absorption in both the neutral and ionic cluster species.     

Elusive O═P≡N, a rare example of phosphorus σ2λ5-coordination

Two linear isomers, OPN and ONP, were formed in an Ar matrix at 16 K by ArF laser (λ = 193 nm) photolysis of phosphoryl triazide, OP(N(3))(3), and comprehensively characterized by their mid- and far-IR spectra as well as (14/15)N isotopic data. Two intermediates, (N(3))(2)P(O)N and N(3)P(O)N(4), have been isolated in an Ar matrix and spectroscopically characterized. Photolysis of these intermediates using near-UV/vis light (λ > 320 nm) was shown to yield exclusively ONP, which under ArF laser irradiation selectively photo-isomerized to OPN. The photochemical and molecular properties of OPN and ONP are discussed on the basis of experimental and ab initio calculated results.     

Biocatalytic microcontact printing

Immobilized biocatalytic lithography is presented as an application of soft lithography. In traditional microcontact printing, diffusion limits resolution of pattern transfer. By using an immobilized catalyst, the lateral resolution of microcontact printing would depend only on the length and flexibility of the tether (<2 nm) as opposed to diffusion (>100 nm). In the work, exonuclease reversibly immobilized on a relief-patterned stamp is used to ablate ssDNA monolayers Percent of ablation was determined via confocal fluorescence microscopy to be approximately 70%.     

The Degradation of the Active Medium of an Argon Fluoride Discharge Lamp with a Noncorrosive Gas Mixture

The results of a spectroscopic study on the degradation of the active medium of an ArF electric-discharge lamp with the He–Ar–SF₆ working mixture (p 100 kPa) and pumped by a transverse space discharge are presented. Plasma radiation spectra were studied over the range 190–780 nm at different stages of degradation of the working mixture, and the dynamics of emission from the inert gases, as well as the products of sulfur hexafluoride degradation in the plasma, were determined. The ArF(B–X) emission band at = 193 nm was observed when the number of discharge pulses was 10³, whereas the quite effective formation of excited sulfur molecules, which decomposed producing emission bands in the spectral region of 260–550 nm, took place at n 10⁴.     

二氧化碳基聚碳酸环己撑酯电子束光刻胶显影工艺优化

电子束光刻是下一代光刻技术中的有力竞争者,在微纳加工尤其是光刻掩膜制造上具有显著的竞争优势。 开发高性能的光刻胶并优化出最佳的显影条件和工艺是提升电子束光刻效率的基础。 本文在前期开发出的二氧化碳基聚碳酸酯电子束光刻胶的基础上,进一步探究了正性聚碳酸环己撑酯(PCHC)胶的显影条件对电子束光刻性能的影响,具体研究了显影剂以及显影温度和时间等工艺条件,筛选出了最优显影剂正己烷,最佳显影温度0 ℃,最佳显影时间30 s。 在该条件下,PCHC的灵敏度和对比度分别为208 μC/cm²和3.06,并实现了53 nm的分辨率,超过了当下广泛使用的PMMA-950k电子束光刻胶,有望为科研院所和半导体加工车间提供一种性能优异、成本低廉的新型电子束光刻胶。     

Second harmonic excitation spectroscopy of silver nanoparticle arrays

Frequency-scanned excitation profiles of coherent second harmonic generation (SHG) were measured for silver nanoparticle arrays prepared by nanosphere lithography. The frequency of the fundamental beam did not coincide with the localized surface plasmon resonance (LSPR) of the nanoparticles and was tuned so that the coherent second harmonic (SH) emission was in the region of the LSPR at 720-750 nm. The SH emission from the arrays was compared with a smooth silver film to identify an enhancement of SH emission efficiency that peaks near approximately 650 nm for nanoparticles 50 nm in height. The polarization and orientation dependence of this enhancement suggests that it is related to a dipolar LSPR mode polarized normal to the plane of the substrate. Linear extinction spectra are dominated by in-plane dipoles and do not show this weak out-of-plane LSPR mode. The nanoparticle arrays are truncated tetrahedrons symmetrically oriented by nanosphere lithography to cancel SH from in-plane dipoles which allows observation of the weak out-of-plane component.