Dual-Component Columnar-Structured Thin Films

双组分柱状结构薄膜

• 批准号: 0504813
• 负责人: Alexander King
• 金额: $ 35.1万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0504813&HistoricalAwards=false
• 关键词: Dual; Component; Columnar; Structured; Thin

TECHNICAL: This project addresses structure-property relationships in polycrystalline thin films, and will seek to exploit the intrinsic structural anisotropy that exists when the films have columnar structures. In these films, grains, grain boundaries, phase boundaries (if they exist), and triple junctions all can be made to extend from the bottom of the film to the top, and therefore provide continuous paths across the film. Some of these paths, however, can be disconnected in the plane of the film: isolated grains of one phase and/or interfacial triple-junctions do not form a continuous path in the plane of the film. When these structural components can be engineered to be the active paths for electron transport, for example, the film will be conductive through its thickness, but not in its plane. A number of other potential applications of isolated columnar structural elements are conceivable, including the low-cost manufacture of large areas covered with field-emitter tips, for use in display systems. The project seeks, first, to develop suitable processing methods to create columnar microstructures with application potential, using two different strategies. The first strategy is the creation of two-phase films, using a binary eutectic alloy system. The goal here is to create a system in which one of the phases forms isolated columns that can be used for a variety of purposes, depending upon the properties that can be associated with the phase in the columns. The second strategy is the creation of columnar active regions by doping the regions defined by triple junctions, in an originally single-phase film. These two strategies are likely to provide differing opportunities for microstructural control, and will also be varyingly applicable in different materials systems. Our exemplar for the first strategy will be the Cu-Ag eutectic system, and for the second strategy we will base our development on films of LiF. Significant new findings are expected relative to the processing and microstructural control of both of these thin film systems. Controllable films with distinct columnar phases or compositional regions (which we identify generically as .components.) will enable the exploration of a number of attractively simple structure-property relationship hypotheses, and the testing of these hypotheses will be an important component of this research. NONTECHNICAL: The project will train two PhD students in advanced processing-structure-property relationships, providing a very sound training for all of materials science, addressing both modeling and experimentation. In addition, as many as twelve undergraduate students may be involved in the research project through summer research programs, or special topics research courses as part of their undergraduate programs. The selection of students for these opportunities will be based upon existing programs at Purdue University, which have significant outreach to minorities and women. The demonstration of fundamentally simple ideas for the creation of special properties via microstructural control is likely to provide a number of opportunities for informal education and outreach, that will be fully exploited in the recruitment of students into the Materials Engineering program at Purdue, and also in presentations to the general public. Strong relationships with the microelectronics industry will ensure that novel properties such as anisotropic electrical conductivity, optoelectronic properties, and others, will be exploited efficiently.

技术支持：本计画探讨多晶薄膜的结构与性质关系，并将探讨薄膜具有柱状结构时所存在的内在结构异向性。在这些膜中，晶粒、晶界、相界（如果它们存在的话）和三重结都可以从膜的底部延伸到顶部，因此提供穿过膜的连续路径。然而，这些路径中的一些可以在膜的平面中断开：一个相和/或界面三重结的孤立晶粒在膜的平面中不形成连续路径。例如，当这些结构组件可以被设计成电子传输的有效路径时，膜将通过其厚度而不是在其平面内导电。隔离的柱状结构元件的许多其他潜在应用是可以想到的，包括用场发射器尖端覆盖的大面积的低成本制造，以用于显示系统。该项目寻求，首先，开发合适的加工方法，以创建具有应用潜力的柱状微观结构，使用两种不同的策略。第一种策略是使用二元共晶合金系统来产生两相膜。这里的目标是创建一个系统，其中一个相形成可以用于各种目的的隔离柱，这取决于可以与柱中的相关联的属性。第二种策略是通过在最初的单相膜中掺杂由三重结限定的区域来创建柱状有源区。这两种策略可能提供不同的机会，微观结构控制，也将在不同的材料系统中不同的适用。第一种策略的范例是Cu-Ag低共熔体系，第二种策略的范例是LiF薄膜。相对于这些薄膜系统的加工和微观结构控制，预计将有重大的新发现。可控膜与不同的柱状相或组成区域（我们确定一般作为.组件。）将使一些有吸引力的简单的结构-性质关系的假设的探索，这些假设的测试将是本研究的一个重要组成部分。非技术性：该项目将培养两名博士生先进的加工结构性能的关系，为所有的材料科学，解决建模和实验提供了一个非常完善的培训。此外，多达12名本科生可以通过暑期研究项目或作为本科课程一部分的专题研究课程参与研究项目。这些机会的学生的选择将基于普渡大学现有的课程，这些课程对少数民族和妇女有很大的影响。通过微观结构控制创建特殊属性的基本简单的想法的演示可能会提供一些非正式教育和推广的机会，这将在普渡大学材料工程课程的学生招聘中得到充分利用，并向公众展示。与微电子行业的密切关系将确保有效利用各向异性电导率、光电子特性等新特性。