Polishing Glass-Ceramics with Ceria

数据存储容量的急剧增加改变了我们使用计算机的方式。陶瓷盘片提供了显着的优势，目前铝基技术。它们更坚固，同时仍然很轻，可以旋转得更快，或者只是移动，而不会增加盘片正常的波动，这会导致磁头崩溃和驱动器故障。玻璃盘片现在正在生产，但玻璃陶瓷盘片将提供更大的性能。抛光陶瓷盘片是困难的，因为材料是硬的，并且在玻璃陶瓷的情况下，它是化学不均匀的。 化学机械抛光（CMP）涉及在表面处破碎材料，同时不产生亚表面损伤，并使表面光滑，以产生比抛光介质中颗粒尺寸光滑100倍的光洁度。二氧化铈目前在抛光玻璃时效果最好，不是因为它特别硬，而是因为它提供了硬度和化学性质的最佳组合。众所周知，接触点的化学性质是一个关键因素-氧化铈抛光总是涉及水。 用于抛光玻璃陶瓷的方法仍在开发中，氧化铈是主要候选物。在这个项目中，学生将使用尖端技术，包括电子显微镜，原子力显微镜和近原子尺度的光谱学。他们将化学和机械方面的训练应用到当今的关键技术中。实际上，器件制造的许多方面都涉及到制造光滑的平面。例如，CMP还用于在构建多层芯片时平坦化层，以及制备光纤的端部以优化互连。在新的高速硬盘驱动器中，支撑磁存储介质的玻璃盘片必须被抛光得如此平坦，以至于在一个三英寸的磁盘上，凸起的高度小于10个原子;将此与平滑美国相比，没有一座山高于几英寸！抛光已经发展成为一门艺术，但我们现在需要了解这门科学，并在艺术和科学方面培养学生。我们的计划解决了两个问题：缺乏基本知识和缺乏训练有素的科学家谁了解CMP的艺术和科学。该项目向材料科学专业的学生展示了为什么他们需要化学、机械工程和电气工程方面的基础课程，以及这些学科如何在工业环境中联合收割机，不仅是为了这个项目，而且是为了CMP的许多应用。我们的跨学科研究计划汇集了来自不同学科的研究生和本科生的多元化群体。学生们会见了我们的工业界同事，并参观了使用这项技术的公司。了解CMP并能更充分地利用最先进仪器的熟练科学家是工业工作场所的国家需求。

Dramatic increases in data-storage capacity have changed how we use computers. Ceramic platters offer significant advantages over current Aluminum-based technology. They are more rigid, while still light, and can be rotated faster, or simply moved, without increased fluctuations normal to the platter that would cause a head crash and drive failure. Glass platters are now in production but glass-ceramic platters would offer even greater performance. Polishing ceramic platters is difficult because the material is hard, and in the case of glass-ceramics, it is chemically inhomogeneous. Chemical-mechanical polishing (CMP) involves fracturing the material at the surface while not creating subsurface damage and smoothing the surface to produce a finish that is 100 times smoother than the size of the particles in the polishing medium. Ceria currently give the best results when polishing glass, not because it is particularly hard, but because it gives the best combination of hardness and chemistry. It is known that the chemistry at the point of contact is a critical factor-ceria polishing always involves water. Methods for polishing glass-ceramics are still being developed with ceria being the primary candidate. In this program, students work with cutting-edge techniques including electron microscopy, atomic-force microscopy and spectroscopy at the near-atomic scale. They apply their training in chemistry and mechanics to today's critical technology.Actually, there are many aspects of device fabrication which involve producing a smooth flat surface. For example, CMP is also used to planarize layers while building multilayer chips and to prepare the ends of optical fibers for optimizing interconnections. In the new high-speed hard-drives, the glass platters which support the magnetic storage media must be polished so flat that bumps are less than 10's of atoms high on a three-inch disk; compare this to smoothing the USA so no hill is higher than a few inches! Polishing has developed as an art but we need now to understand the science and to train students in both the art and the science. Our program addresses two problems: a lack of basic knowledge and the shortage of trained scientists who understand the art and science of CMP. This project shows students in materials science why they need those basic courses in chemistry, mechanical engineering and electrical engineering and how these disciplines combine in an industrial setting, not just for this project but for many applications of CMP. Our interdisciplinary research program brings together a diverse group of graduate and undergraduate students from different disciplines. The students meet our industrial colleagues, and visit the companies working with this technology. Skilled scientists who understand CMP and can fuller utilize the state-of-the-art instrumentation are a national need in the industrial workplace.