CAREER: Theory of Epitaxial-Oxide-Semiconductor Nanosystems

职业：外延氧化物半导体纳米系统理论

• 批准号: 0548182
• 负责人: Alexander Demkov
• 金额: $ 40万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0548182&HistoricalAwards=false
• 关键词: CAREER; Theory; Epitaxial; Oxide; Semiconductor

TECHNICAL SUMMARY:This CAREER award supports computational and theoretical research that aims to develop a theoretical framework for epitaxial-oxide-semiconductor nanosystems and education in computational materials research targeted on undergraduate and high-school students.Crystalline epitaxial oxides on semiconductors (COS) open a new avenue for complementary metal oxide semiconductor (CMOS) technology utilizing materials other than Si, e.g. Ge or GaAs. Other applications of COS are at the end of the Si technology roadmap; the main advantage of a crystalline oxide is its epitaxial registry to the Si substrate that results in superior device performance by eliminating interfacial defects. COS combined with recently discovered epitaxial semiconductors on oxides (SOX) provides another set of exciting possibilities to explore. The PI aims to develop a comprehensive theoretical framework for the emerging field of nanoscale epitaxial oxide semiconductor systems. The research focuses on fundamental problems in two areas:1. Crystal growth of oxide-semiconductor and semiconductor-oxide systems.2. "Tunability" of the electronic and transport properties of epitaxial oxide-semiconductor nanosystems.The key to successful oxide-semiconductor heteroepitaxy is to achieve two-dimensional or Frank-Van der Merwe growth. In addition to lattice and thermal mismatch, the transition between fundamentally different types of bonding across the interface must be considered. The PI will investigate the use of intermetallic Zintl compounds as transition layers between ionic oxides and covalent semiconductors. The central idea is to exploit the intrinsic charge transfer in a Zintl compound to force the more electronegative metal to assume semi-covalent bonding which continues into the semiconductor. Two other key problems are the 90 twin domains caused by breaking of the symmetry across the interfaces (e.g. zinc-blende to perovskite), and step incommensurability between two materials. Relating the atomic geometry and electronic structure of the nanoassembly to its electrical properties, such as charge transfer and retention, will enable the PI to assess possible applications of these systems. The approach is based on ab-initio total energy methods and atomic-scale electron transport techniques that the PI has recently developed. The work will entail close collaboration with experimentalists in academia and industry.To bring the excitement of practical theoretical nanoscience into undergraduate education, the PI plans to develop, improve, and enhance a new course entitled "Practicum on Computational Materials for Nanotechnology." This course will be offered to senior year students in Physics, Chemistry, Electrical Engineering, and Chemical Engineering. An outreach program aimed at attracting female high-school students to nanoscience will also be developed in collaboration with the Physics instructor at the LBJ Science Academy, a magnet high school with a large number of minority students. The PI aims to create an opportunity for female students to spend summers with the PI's research group to learn about computational nanoscience. This activity will be coordinated with a successful existing UTEACH program at UT.NON-TECHNICAL SUMMARY:This CAREER award supports computational and theoretical research that aims to develop a theoretical understanding of nanosystems and structures on semiconductor surfaces and education in computational materials research with a focus on undergraduates.The PI will use advanced computational tools that start from the constituent atoms to study how oxide materials can be grown on the surfaces of semiconductors, with an emphasis on materials other than silicon, the current workhorse of the electronics industry. The PI will also study the electronic properties of the resulting nanosystems. The PI will focus on fundamental materials science and surface science problems. The work helps lay the theoretical foundations for semiconductor electronic devices with significantly higher performance and enhanced functionality as compared to current electronic device technology. The PI will also explore new phenomena that may arise in these unusual systems. To bring the excitement of practical theoretical nanoscience into undergraduate education, the PI plans to develop, improve, and enhance a new course entitled "Practicum on Computational Materials for Nanotechnology." This course will be offered to senior year students in Physics, Chemistry, Electrical Engineering, and Chemical Engineering. An outreach program aimed at attracting female high-school students to nanoscience will also be developed in collaboration with the Physics instructor at the LBJ Science Academy, a magnet high school with a large number of minority students. The PI aims to create an opportunity for female students to spend summers with the PI's research group to learn about computational nanoscience. This activity will be coordinated with a successful existing UTEACH program at UT.

技术概要：该职业奖支持旨在为外延氧化物半导体纳米系统开发理论框架的计算和理论研究，以及针对本科生和高中生的计算材料研究教育。半导体上的晶体外延氧化物（COS）为利用除Si以外的材料（如Ge或GaAs）的互补金属氧化物半导体（CMOS）技术开辟了新的途径。COS的其他应用处于Si技术路线图的末端;晶体氧化物的主要优点是其与Si衬底的外延配准，通过消除界面缺陷而产生上级器件性能。COS与最近发现的氧化物上外延半导体（SOX）相结合，提供了另一组令人兴奋的探索可能性。PI旨在为纳米级外延氧化物半导体系统的新兴领域开发一个全面的理论框架。研究主要集中在两个方面的基本问题：1。氧化物-半导体及半导体-氧化物系统的晶体生长.外延氧化物-半导体纳米系统的电子和输运性质的“可调谐性”。成功的氧化物-半导体异质外延的关键是实现二维或Frank-Van der Merwe生长。除了晶格和热失配之外，还必须考虑界面上根本不同类型的键合之间的过渡。PI将研究使用金属间Zintl化合物作为离子氧化物和共价半导体之间的过渡层。其核心思想是利用Zintl化合物中固有的电荷转移，迫使电负性更强的金属呈现半共价键，并继续进入半导体。另外两个关键问题是由界面对称性的破坏（例如锌-钙钛矿）引起的90孪晶畴，以及两种材料之间的阶跃不相容性。将纳米组装体的原子几何形状和电子结构与其电学性质（如电荷转移和保留）联系起来，将使PI能够评估这些系统的可能应用。该方法是基于从头算总能量方法和原子尺度的电子输运技术，PI最近开发的。这项工作将需要与学术界和工业界的实验人员密切合作。为了将实用理论纳米科学的兴奋带入本科教育，PI计划开发，改进和加强一门名为“纳米技术计算材料实习”的新课程。“本课程将提供给物理，化学，电气工程和化学工程的高年级学生。还将与LBJ科学学院的物理教师合作制定一项旨在吸引女高中生学习纳米科学的外联方案，LBJ科学学院是一所拥有大量少数民族学生的磁铁高中。PI的目的是为女学生创造一个机会，与PI的研究小组一起度过暑假，学习计算纳米科学。这项活动将与UT现有的一个成功的UTEACH项目相协调。非技术概要：该职业奖支持旨在发展对半导体表面纳米系统和结构的理论理解的计算和理论研究，以及以本科生为重点的计算材料研究教育。PI将使用先进的计算工具，从组成原子开始研究氧化物材料如何在半导体表面生长，重点是硅以外的材料，目前硅是电子工业的主力。PI还将研究由此产生的纳米系统的电子特性。PI将专注于基础材料科学和表面科学问题。这项工作有助于为半导体电子器件奠定理论基础，与当前的电子器件技术相比，具有显着更高的性能和增强的功能。PI还将探索这些不寻常系统中可能出现的新现象。为了将实用理论纳米科学的兴奋带入本科教育，PI计划开发，改进和加强一门名为“纳米技术计算材料实习”的新课程。“本课程将提供给物理，化学，电气工程和化学工程的高年级学生。还将与LBJ科学学院的物理教师合作制定一项旨在吸引女高中生学习纳米科学的外联方案，LBJ科学学院是一所拥有大量少数民族学生的磁铁高中。PI的目的是为女学生创造一个机会，与PI的研究小组一起度过暑假，学习计算纳米科学。这项活动将与UT现有的成功UTEACH计划协调。