表面等离子体超分辨光刻装置关键技术研究

发布时间：2018-03-21 22:06

本文选题：衍射极限　切入点：对准　出处：《中国科学院光电技术研究所》2017年博士论文　论文类型：学位论文

【摘要】：从集成电路的概念提出以来,光刻技术得到了长足的发展。传统投影透镜成像光刻方法在进入到纳米尺度时,面临着难以逾越的经济成本挑战。在保证经济性的前提下,迫切需要发明创新的技术来满足下一代集成电路的制造需求。尽管极紫外光刻与193nm的浸入式光刻系统通过双重曝光可以制作22nm及更小特征尺寸的图形,但是面临着大规模生产的高成本与可靠性问题。本课题提出了一种低成本、高分辨率的表面等离子体纳米成像光刻方法。表面等离子体光刻虽是一种潜在的超分辨力和低成本光刻方法,但是,仍受限于近场衍射极限(照明光波长与短工作距)。在深亚波长分辨力的接近式表面等离子体透镜光刻实验中,分辨力越高,光刻工作距越短。本文通过调制表面等离子体透镜的物图形衍射的频谱分布,结合操控像平面处电场分量,实现倏逝波在成像过程中放大增强,从而突破近场衍射极限,拓展接近式表面等离子体光刻的工作距,提高成像分辨力。并基于该原理,开展了表面等离子体光刻装置原型的相关关键技术研究。对准方法是集成电路制造和其它多层纳米结构制作必需的关键技术。该原型使用周期近似的两组光栅叠加产生莫尔条纹获得了灵敏度达到10nm的对准信号。根据衍射理论,莫尔条纹独立于照明光波长和掩模与样片间的间隙,这使得莫尔条纹非常适合应用在表面等离子体超分辨光刻装置中。然而,仅使用莫尔条纹信号并不能保证掩模和样片的绝对对准,因为当掩模和样片偏移固定位移时,莫尔条纹将重复出现。为了消除这种不确定状态,在样片和掩模上的光栅对准标记旁边,分别设计了“方框”和“十字”对准标记。该原型的自动对准方法采用了粗、精两级对准方法。为了验证对准方法的可行性,我们开展了平面套刻实验,实验结果证明,该原型通过粗精两级对准方法,在1cm2的面积上获得了100nm的套刻精度。该自动对准方法可以完全扩展用于4英寸或更大面积样片的套刻对准。如果针对样片掩模间图形的偏差进行匹配补偿、采用更高精度的运动平台和精确的环境控制方法,表面等离子体原型可以获得更高的套刻精度。在表面等离子体光刻原型中,采用金属-光刻胶-金属形式的等离子体共振腔透镜来放大渐逝波,从而克服常规近场光刻所遇到的低保真度、低对比度和短的工作距问题。使用波长为365nm的Hg灯光源,实验中获得了具有高分辨率、高对比度的曝光图像。该原型成功的实现了具有60nm线宽和120nm周期的光栅阵列图案的曝光。通过该原型的步进方法,制作了5×5的光栅阵列图案,阵列图案的步长达到300μm,在约2×2mm2的大面积范围内获得了良好的图形一致性。特别是在掩模面积远小于曝光区域的条件下,步进曝光功能使该原型获得了大面积图案曝光能力。本文的研究目标是设计、制造、装配和校准一台先进的表面等离子体超分辨光刻装置原型。该原型使用365nm波长的紫外光源,获得了32nm图形的曝光能力。此外,该原型还兼容传统光刻工艺,具有高度灵活的、友好的用户体验,并且具有大面积图形曝光能力和精确的多次图形套刻能力。该原型不限于固定的掩模图案,具备任意图形的曝光能力,为开展高分辨、低成本、高效纳米光学光刻技术提供重要方法和技术途径,为下一代低成本的纳米结构制作技术提供了一条可能的路径。
[Abstract]:Since it was put forward from the concept of integrated circuits, lithography technology has got considerable development. The traditional projection lens imaging lithography method into the nano scale, facing the challenge of insurmountable economic cost. In the premise of ensuring economy, technology innovation urgently needed to meet the demand of integrated circuit manufacturing. Although the next generation immersion lithography system for extreme ultraviolet lithography and 193nm by double exposure can produce 22nm and smaller feature size of the graphics, but faced with high cost and reliability problems of mass production. This paper puts forward a kind of low cost, nanoplasmonic imaging method for high resolution lithography. Surface plasmon lithography is a super the resolution of the potential and low cost lithography method, however, is still limited by the near-field diffraction limit (illumination wavelength and shorter distance). In the deep sub wavelength resolution of the proximity Surface plasma lens lithography experiment, the higher the resolution, the shorter the distance lithography. The spectrum of object graphics diffraction modulation surface plasmon lens distribution, combined with the control plane like electric field component, amplify evanescent wave enhancement in the imaging process, from which break the near-field diffraction limit, expand the near surface plasma lithography working distance, improve the imaging resolution. Based on this principle, research on the key technology of surface plasmon lithography device prototype. The alignment method is made the key technology required for integrated circuit manufacturing and other multilayer structure. The two groups using the approximate periodic grating superposition prototype of Moire fringe obtained with sensitivity to alignment the signal of 10nm. According to the diffraction theory, moire fringe is independent of illumination light wavelength and the gap between the sample and the mask mode, which makes the moire fringe very Suitable for application in surface plasmon super-resolution lithography device. However, only the use of Moire fringe signal does not guarantee the absolute alignment of mask and wafer, because when the mask and the fixed sample offset displacement, moire fringe is repeated. In order to eliminate the uncertainty, in the sample and the mask grating marks next to, were designed to "square" and "cross" alignment mark. Automatic alignment method of the prototype uses a coarse, two fine alignment method. In order to verify the feasibility of the alignment method, we carried out a set of plane experiments. The experimental results show that the prototype through the two grade of coarse and fine alignment method, the accuracy of the moment 100nm in the 1cm2 area. The automatic alignment method can be fully extended to 4 inches or more area of sample alignment. If the sample moment deviation between mask graphics matching compensation recovery Control method for motion platform with higher accuracy and precision of the prototype environment, surface plasmon can obtain higher alignment precision. The surface plasmon lithography prototype, the plasmon resonance cavity lens metal photoresist metal form to amplify evanescent wave, thereby overcoming the conventional near field photolithography with low fidelity of low contrast and short working distance. The use of the wavelength of the light source of Hg 365nm, obtained with high resolution, high contrast image exposure. The prototype of the successful implementation of the grating array pattern with 60NM width and 120nm period of exposure. Through the prototype step method, production the grating array pattern 5 x 5 array pattern, step up to 300 m, the graphics good consistency in the large area of about 2 x 2mm2. Especially in the area of the mask is far less than the exposure area under the condition of step In the exposure function prototype obtained large pattern exposure. The goal of this paper is to design, manufacture, assembly and calibration of an advanced surface plasmon super-resolution lithography device prototype. The prototype using UV light of 365nm wavelength, the exposure ability of 32nm graphics. In addition, the prototype is also compatible with traditional lithography process, highly flexible, friendly user experience, and has a large area patterning ability and precise multiple graphics overlay. The prototype is not limited to the mask pattern is fixed, the exposure ability for arbitrary graphics, high resolution, low cost, high performance nano provide important methods and techniques of optical lithography technology that provides a possible path for the fabrication technology of nano structure and low cost of the next generation.

【学位授予单位】：中国科学院光电技术研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN305.7

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