Control of Defect Interactions for P-Type Doping of ZnO by Ion Implantation

离子注入控制 ZnO P 型掺杂的缺陷相互作用

• 批准号: 0406502
• 负责人: Gabriel Braunstein
• 金额: $ 5万
• 依托单位: The University of Central Florida Board of Trustees
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0406502&HistoricalAwards=false
• 关键词: Control; Defect; Interactions; Type; Doping

This is a Minority Career Advancement Award (MCAA) project addressing selective-area formation of p-type transparent conducting oxides (TCOs), and wide band gap semiconductors, using ion implantation, with focus on ZnO as a representative material. The doping approach involves ion implantation at a temperature low enough to freeze interstitials created by ion beam irradiation so as to avoid creation of a defect imbalance that precludes proper annealing of implantation-induced lattice damage. Low temperature implantation will be followed by a very rapid in-situ heating of the sample, to induce short range, interstitial-vacancy recombination, and substitutional lattice location of the dopants. An ex-situ annealing will then be carried out to further an-neal any residual lattice defects, and enhance electrical activation of the dopants. By controlling the mobility and recombination of defects, and by carefully monitoring the lattice location of po-tential dopants, and the electrical transport properties of the implanted layers, fundamental in-formation is sought regarding mechanisms responsible for the doping difficulties typically encountered in ZnO, and other wide band gap semiconductors. Implanted and annealed samples will be characterized for their structural, compositional, optical, and electronic transport properties. Measurements of lattice disorder and dopant concentration as a function of depth, will be performed and correlated with optical and electronic transport analyses: Rutherford backscattering spectrometry will be employed to determine stoichiometry, composition as a function of depth, and the presence of impurities in the films. Ion channeling measurements will be used to monitor implantation induced lattice damage, and to assess the lattice location of the dopants (in single crystals). The depth profiles of ion implanted species, as well as host substrate compo-nents, and impurities, will be studied with secondary ion mass spectrometry. Optical properties will be analyzed by spectrophotometry, in transmission and reflection modes. Electronic trans-port properties will be characterized by Hall effect and conductivity measurements, as a function of temperature. This research is expected to advance understanding of the role of defects on the electrical transport properties of ZnO, and other wide band gap semiconductors, and in the de-velopment of an approach for spatially controlled doping of ZnO based devices. %%% The project addresses fundamental research issues associated with electronic materials having technological relevance. An important feature of the project is the integration of research and education. Broader impacts associated with the project are exemplified by education and training of undergraduate and graduate students in materials research topics and methodologies; incorporation of the materials developed in the research activity in a graduate/undergraduate class on ion-solid interactions; a strong emphasis on attracting students from underrepresented groups; establishment of scientific collaborations with groups from Latin America; fostering of activities for students (graduate, undergraduate, high school) such as technical symposia and poster session competitions at the local level (Florida State); development of science workshops for high and middle school science teachers in collaboration with Orlando Science Center; and dissemination of scientific information by publishing the results, and posting on a designated website (within the Physics Department website: www.physics.ucf.edu).

这是一个少数族裔职业进步奖 (MCAA) 项目，致力于使用离子注入选择性区域形成 p 型透明导电氧化物 (TCO) 和宽带隙半导体，重点关注 ZnO 作为代表性材料。掺杂方法涉及在足够低的温度下进行离子注入，以冻结离子束照射产生的间隙，以避免产生缺陷不平衡，从而妨碍对注入引起的晶格损伤进行适当的退火。低温注入之后将对样品进行非常快速的原位加热，以诱导掺杂剂的短程、间隙空位复合和替代晶格位置。然后将进行异位退火，以进一步退火任何残留的晶格缺陷，并增强掺杂剂的电激活。通过控制缺陷的迁移率和复合，并仔细监测潜在掺杂剂的晶格位置以及注入层的电传输特性，寻找有关 ZnO 和其他宽带隙半导体中通常遇到的掺杂困难的机制的基本信息。注入和退火样品的结构、成分、光学和电子传输特性将得到表征。将进行晶格无序和掺杂剂浓度作为深度函数的测量，并将其与光学和电子传输分析相关联：卢瑟福背散射光谱法将用于确定化学计量、作为深度函数的成分以及薄膜中杂质的存在。离子通道测量将用于监测注入引起的晶格损伤，并评估掺杂剂的晶格位置（在单晶中）。离子注入物质以及基质成分和杂质的深度分布将通过二次离子质谱法进行研究。将通过分光光度法在透射和反射模式下分析光学特性。电子传输特性将通过霍尔效应和电导率测量来表征，作为温度的函数。这项研究预计将加深对缺陷对 ZnO 和其他宽带隙半导体电传输特性的影响的理解，并有助于开发基于 ZnO 的器件的空间控制掺杂方法。 %%% 该项目解决与具有技术相关性的电子材料相关的基础研究问题。该项目的一个重要特点是研究与教育的融合。与该项目相关的更广泛影响体现在本科生和研究生在材料研究主题和方法方面的教育和培训；将离子-固体相互作用研究活动中开发的材料纳入研究生/本科生课程；非常重视吸引来自代表性不足群体的学生；与拉丁美洲团体建立科学合作；促进学生（研究生、本科生、高中）的活动，例如地方层面的技术研讨会和海报比赛（佛罗里达州）；与奥兰多科学中心合作，为高中和初中科学教师举办科学讲习班；通过发布结果并在指定网站上发布（物理系网站内：www.physicals.ucf.edu）来传播科学信息。