GOALI - Particle Adhesion in Semiconductor Wafer Cleaning

这项拟议的研究是对微电子界感兴趣的微纳米级颗粒与纳米结构晶圆的粘附性的理论和实验相结合的研究。目前微电子工业还没有清洁未来晶圆的可制造技术。特别是晶圆上感兴趣的图案太脆弱，无法受到现有清洁方法的影响。新清洁技术的发展需要了解污染物的粘附力，但晶圆上图案的长度尺度正在迅速接近控制颗粒粘附的基本力的长度尺度。这项工作将测量和模拟这种附着力。这项工作的智力价值在于新的理论和实验方法可以用于分类微纳米尺度颗粒对粗糙纳米图案或纳米层状表面的粘附。新的理论描述，有限的，图案表面对范德华力和表面之间的静电附着力的影响将发展和实验验证。如果毛细力出现，研究中已经作出了测量和模拟毛细力的规定。胶体探针显微镜将被执行，以允许基材和颗粒之间的附着力直接测量。使用聚焦离子束/扫描电子显微镜（FIB/SEM）或扫描透射电子显微镜/能量过滤透射电子显微镜（STEM/EFTEM）以纳米级精度创建粒子几何和形态的3D地图，将允许创建粒子表面的详细模型。这些将用于预测观察到的粘附力的力模型。这样的模型将是此类模型中的第一个。这项工作的更广泛影响以几种方式阐述。首先，这项工作的技术成果对微电子行业具有深远的重要性，因为该行业目前没有可制造的方法来清洁未来的晶圆和光罩。颗粒粘附对制药行业也至关重要，因为制药行业的颗粒流动和颗粒混合是必不可少的过程，而在国土安全事务中，对炸药、生物制剂或放射性制剂的纳米和微颗粒进行采样和传感是必要的。这项工作还将成为当地一所小学的推广工作的一部分，该小学每年将有120多名二年级学生和6名教师参与。学生和老师将以小组形式前往普渡大学，使用AFM制作树叶、草、cd、dvd、指甲、头发和皮肤的地形图。他们将利用收集到的图像，用博多因和教学人员共同开发的课程来强化他们在课堂上学习的内容。这项工作的行业合作伙伴FSI国际（FSI）将提供晶圆、颗粒沉积能力、晶圆清洁能力和评估晶圆清洁效率的计量方法。Beaudoin将对FSI提供的晶圆进行颗粒粘附和建模研究，并将这些研究结果反馈给FSI。反过来，FSI将利用这些结果来优化其低温气溶胶基晶圆清洗机的操作，并将记录Beaudoin粘附模型的准确性。FSI还将在每年夏天接待博多安的学生一个月，在FSI的工业环境中进行实验。

CBET-0829086BeaudoinThis proposed research is a combined theoretical and experimental study of the adhesion of micro- and nano-scale particles to nano-structured wafers of interest to the microelectronics community. At present the microelectronics industry has no manufacturable technologies for cleaning future wafers. In particular, the patterns of interest on the wafers are too fragile to be subjected to existing cleaning approaches. The development of new cleaning technologies requires understanding of the contaminant adhesion forces, but the length scales of the patterns on the wafers are rapidly approaching the length scales of the basic forces that control the particle adhesion. This work will measure and model this adhesion. The Intellectual Merit of the proposed work lies in the new theoretical and experimental methods to be employed to categorize the adhesion of micro- and nano-scale particles to rough nano-patterned or nano-layered surfaces. New theoretical descriptions of the effects of finite, patterned surfaces on the van der Waals and electrostatic adhesion forces between the surfaces will be developed and validated experimentally. Provisions within the research have been made to measure and model capillary forces, should they arise. Colloidal probe microscopy will be performed to allow adhesion forces between the substrates and the particles to be measured directly. The use of focused ion beam/scanning electron microscopy (FIB/SEM) or scanning transmission electron microscopy/energy-filtered transmission electron microscopy (STEM/EFTEM) to create 3D maps of particle geometry and morphology with nano-scale precision will allow creation of detailed models of the particle surfaces. These will be used in force models that predict the observed adhesion. Such models will be the first of their kind. The Broader Impacts of this work are articulated in several fashions. First, the technical results of the work are of profound importance to the microelectonics industry, as the industry currently possesses no manufacturable approaches for cleaning future wafers and photomasks. Particle adhesion is also critically important to the pharmaceutical industry where particle flows and particle mixing are essential processes, and in homeland security matters, where sampling and sensing of nano- and micro-particles of explosives, biological agents, or radioactive agents is necessary. The proposed work will also be part of an outreach effort to a local elementary school that will involve over 120 second graders and 6 teachers each year. The students and teachers will travel to Purdue in small groups and will use the AFM to make topographical maps of leaves, grass, CDs, DVDs, fingernails, hair and skin. They will take the images they collect and use them to reinforce the content they are learning in the classroom using lessons jointly developed by Beaudoin and the teaching staff. The industry partner in this work, FSI International (FSI), will provide wafers, particle deposition capability, wafer cleaning capability, and metrology for evaluating wafer cleaning effectiveness. Beaudoin will perform particle adhesion and modeling studies on the wafers provided by FSI, and will feed the results of these studies back to FSI. FSI, in turn, will use these results to optimize the operation of its cryogenic aerosol-based wafer cleaner, and will document the accuracy of Beaudoin's adhesion models. FSI also will host Beaudoin's student for one month each summer to perform experiments in an industrial setting at FSI.