Materials Processing for ZnO

氧化锌材料加工

• 批准号: 0400416
• 负责人: Stephen Pearton
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0400416&HistoricalAwards=false
• 关键词: Materials; Processing; ZnO

This project focuses on two research areas related to utilization of ZnO as a technological mate-rial-ohmic contact formation, and the exploration and potential exploitation of ferromagnetism in doped ZnO. Greater understanding of fundamental materials science associated with stable, low resistance ohmic contacts to ZnO; plasma chemistries for dry etching of ZnO; implanta-tion/isolation needed in selective area doping for contact formation and for intra-device electrical and optical isolation; and the role of hydrogen on electrical and magnetic properties of ZnO is sought. Rationale for the project includes potential ZnO application to UV light emitters, varistors, transparent high power electronics, surface acoustic wave devices, piezoelectric transducers, gas-sensing and as a window material for display and solar cells. It has advantages relative to GaN because of its availability in bulk, single crystal form and its larger exciton binding energy (~60meV, cf. ~25meV for GaN). In addition, ZnO is lattice-matched to InGaN at an In composition of ~22%, raising the possibility of integration of the two materials to provide enhanced functionality. This may have applications in high-density data storage systems, solid-state lighting (where white light is obtained from phosphors excited by blue or UV light-emitting diodes), se-cure communications and biodetection. The properties of ZnO compare well with those of GaN. ZnO is a direct bandgap semiconductor with Eg = 3.2 eV. The bandgap can be tuned via divalent substitution on the cation site. Cd substitution leads to a reduction in the bandgap to ~ 3.0 eV. Substituting Mg on the Zn site can increase the bandgap to approximately 4.0 eV while still maintaining the wurtzite structure. The electron Hall mobility in ZnO single crystals is on the order of 200 cm2/V-sec at room temperature. The electron mobility is slightly lower than for GaN, but ZnO has a higher saturation velocity. %%% This project addresses basic research issues in a topical area of materials science with significant technological relevance, and places emphasis on the integration of research and education. At least two undergraduates will be included in this project. Persons from under-represented groups (women, minorities) will be particularly encouraged to participate. Additionally, as part of this grant activity, the PI will host 2 students attending the U. FL Student Science Training Program, which is run during the summer by the U. FL Center for Precollegiate Education and Training. This program, now in its 41st year, brings in 10th and llth grade students to actively participate in science and engineering research. The Center for Precollegiate Education and Training at the University of Florida also runs an NSF Teacher Research Update Experience (TRUE) program during the summer. The PI will present a lecture on ZnO at the program and will collaborate with interested teachers to translate the research experience here into modules, which can be taken back to the middle and high schools. ***

本计画的研究方向为利用氧化锌作为欧姆接触材料及探讨掺杂氧化锌的铁磁性。更好地理解与ZnO的稳定，低电阻欧姆接触相关的基础材料科学; ZnO干法蚀刻的等离子体化学;选择性区域掺杂接触形成和器件内电气和光学隔离所需的掺杂/隔离;以及氢对ZnO电气和磁性的作用。该项目的理由包括ZnO在紫外光发射器、压敏电阻、透明高功率电子器件、表面声波器件、压电换能器、气体传感以及作为显示器和太阳能电池的窗口材料方面的潜在应用。它相对于GaN具有优势，因为它的可用性在块体，单晶形式和其较大的激子结合能（〜 60 meV，参见图1）。~ 25 meV（对于GaN）。此外，ZnO与In成分约为22%的InGaN晶格匹配，提高了两种材料集成以提供增强功能的可能性。这可以应用于高密度数据存储系统、固态照明（其中白色光是从由蓝色或UV发光二极管激发的磷光体获得的）、半导体通信和生物检测。ZnO的性能与GaN的性能相当。ZnO是直接带隙半导体，Eg = 3.2 eV。可以通过阳离子位点上的二价取代来调节带隙。Cd取代导致带隙减小至~ 3.0 eV。在Zn位点上取代Mg可以将带隙增加到约4.0eV，同时仍然保持纤锌矿结构。ZnO单晶中的电子霍尔迁移率在室温下为200 cm 2/V-sec。电子迁移率略低于GaN，但ZnO具有更高的饱和速度。%%% 该项目涉及材料科学领域的基础研究问题，具有重要的技术相关性，并强调研究和教育的整合。至少有两名本科生将被纳入本项目。将特别鼓励代表性不足的群体（妇女、少数民族）的人参加。此外，作为这项赠款活动的一部分，PI将主办2名学生参加美国。佛罗里达州学生科学培训计划，这是在夏季运行的美国。佛罗里达大学前教育和培训中心。该计划，现在在其第41个年头，带来了10和11年级的学生积极参与科学和工程研究。佛罗里达大学的大学前教育和培训中心也在夏季开展NSF教师研究更新体验（TRUE）项目。PI将在该项目中进行有关ZnO的讲座，并将与感兴趣的教师合作，将这里的研究经验转化为模块，然后可以带回初中和高中。***