GOALI:A Study of Point Defects in Thick, Free-Standing Acceptor-Doped GaN

目标：厚独立受主掺杂 GaN 中点缺陷的研究

• 批准号: 1606765
• 负责人: Mary Ellen Zvanut
• 金额: $ 40.2万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1606765&HistoricalAwards=false
• 关键词: GOALI; Study; Point; Defects; Thick

Nontechnical description: Semiconductors are a class of materials that has enabled the development of most modern electronics including tablets, cell phones, and medical diagnostic equipment. Gallium nitride, the semiconductor studied in this project, was the focus of the 2014 Nobel Prize in Physics because its special material properties made possible the energy efficient LED lighting now familiar to many homeowners. Surprisingly, material and structural imperfections are a necessary part of the successful application of this semiconductor. For this reason, the present research project investigates the properties of a certain class of imperfections that act as traps for electrons. Both fundamental and practical information are determined from the electronic and structural studies. In addition to the basic educational benefits afforded students working on this technologically significant issue, students gain first-hand knowledge and learn about potential advances from industrial personnel who actively grow the materials and devices.Technical description: The project is designed to better understand the acceptor impurities in GaN by microscopically investigating their structure and charge state. The specific focus is electron paramagnetic resonance (EPR) measurements of mm-thick free-standing crystals of GaN doped with technologically important acceptors such as magnesium and carbon. Until recently, EPR of GaN has been hampered by the limited total number of defects and non-uniform strain inherent to thin films. The availability of thick free-standing GaN crystals increases the number of detectable centers and minimizes strain, thus enabling the study of characteristics uniquely addressed by EPR, such as charge state and local structure. In addition, the potential influence of the defects on device properties is investigated with the help of a GOALI partner, Kyma Tech. The study provides previously unavailable fundamental properties such as defect symmetry, and the determination of practical information such as association of a specific defect with an energy level. Overall, the results enhance the understanding of the role of point defects in both bulk and thin film acceptor-doped GaN.

非技术性描述：半导体是一类材料，它使大多数现代电子产品的发展成为可能，包括平板电脑，手机和医疗诊断设备。该项目中研究的半导体氮化镓是2014年诺贝尔物理学奖的焦点，因为其特殊的材料特性使许多房主现在熟悉的节能LED照明成为可能。 令人惊讶的是，材料和结构缺陷是这种半导体成功应用的必要部分。出于这个原因，本研究项目调查了作为电子陷阱的某类缺陷的性质。从电子和结构研究中确定了基础和实用信息。 除了为从事这一技术重大问题的学生提供基本的教育福利外，学生还可以获得第一手知识，并从积极开发材料和器件的工业人员那里了解潜在的进步。技术说明：该项目旨在通过显微镜研究GaN中的受主杂质的结构和电荷状态，更好地了解它们。具体的重点是电子顺磁共振（EPR）测量毫米厚的独立的GaN晶体掺杂技术上重要的受体，如镁和碳。直到最近，GaN的EPR一直受到薄膜固有的缺陷总数有限和应变不均匀的阻碍。厚的独立GaN晶体的可用性增加了可检测中心的数量并最大限度地减少了应变，从而能够研究EPR唯一解决的特性，例如电荷状态和局部结构。此外，在GOALI合作伙伴Kyma Tech的帮助下，研究了缺陷对器件性能的潜在影响。 这项研究提供了以前不可用的基本属性，如缺陷对称性，并确定实际的信息，如关联的一个特定的缺陷与能级。 总体而言，结果提高了对点缺陷在体和薄膜受主掺杂GaN中的作用的理解。