RUI: Growth and Characterization of Epitaxial Zinc Oxide Films for Device Applications

非技术描述氧化锌(ZnO)是一种有吸引力的半导体材料，因为其独特的特性，如更好的电子和光学性能，更大的辐射硬度，相对容易的合成，以及更环保的。因此，它可用于制造太阳能电池、发光体(例如发光二极管(LED)和激光二极管)、用于高功率和高温应用的电子器件、传感器和高密度数据存储系统。这些应用大多需要n型和p型氧化锌材料。虽然高质量的n型氧化锌材料很容易获得，但事实证明，开发p型氧化锌材料是困难的。本研究将探讨制备高导电性p型氧化锌材料的三角掺杂技术。这项技术已经在其他半导体材料上被证明是成功的，它包括将p型掺杂原子限制在宿主氧化锌材料的窄层中。随着p型氧化锌材料的成功开发，该项目将对经济增长、节能和环境保护工作产生积极影响。该项目将利用尖端技术为研究生和本科生提供半导体材料研究方面的教育和培训，为他们从事高科技职业或进一步研究生教育做准备，并将与吸引多个理工系学生的凝聚态物理课程相结合。技术描述尽管氧化锌与GaN具有几种电子和光学性质，但它具有更高的激子结合能、更高的辐射硬度、批量可用，并且需要更简单的晶体生长和加工技术。这些优点使其在制造各种电子、光学和自旋电子器件方面具有独特的吸引力。然而，高本征n型杂质浓度的存在阻碍了器件制造所需的高质量p型氧化锌材料的获得。本项目的目标是通过磁控溅射沉积的方法获得高导电性的p型氧化锌薄膜。Delta掺杂已经成功地在许多具有类似p型掺杂挑战的宽禁带半导体中产生了增强的p型掺杂。P型掺杂原子将在空间上被限制在一个狭窄的层中，从而形成具有独特的V型势垒的二维掺杂密度分布，这超过了常用的均匀掺杂的溶解度极限。该项目可能会带来变革性的结果，因为它不仅将影响半导体器件的开发，而且还将使与掺杂轮廓小型化的基本限制相关的基础科学研究成为可能。

NON-TECHNICAL DESCRIPTION Zinc oxide (ZnO) is an attractive semiconductor material because of its unique characteristics such as better electronic and optical properties, greater radiation hardness, relative ease of its synthesis, and greater environmental friendliness. It is therefore useful for the fabrication of solar cells, light emitters (e.g., light emitting diodes(LEDs) and laser diodes), electronic devices for high power and high temperature applications, sensors and high-density data storage systems. Most of these applications require both n-type and p-type zinc oxide materials. While high quality n-type ZnO materials are readily available, it has proved difficult to develop p-type ZnO materials. This research will investigate the technique of delta-doping for the production of highly conductive p-type ZnO materials. This technique, which has proved successful with other semiconductor materials, involves confining p-type doping atoms in a narrow layer of the host ZnO material. With successful development of p-type ZnO materials, this project could make positive impact to the economic growth, energy savings, and environmental conservation efforts. This project will provide education and training of graduate and undergraduate students in semiconductor materials research using cutting-edge techniques that will prepare them for hi-tech careers or further graduate education, and will also be integrated with the Condensed Matter Physics course that attracts students from several science and engineering departments. Outreach to K-12 students as well as participation of YSU students from the underrepresented groups (women and minorities) will be pursued.TECHNICAL DESCRIPTIONWhile ZnO shares several electronic and optical properties with GaN, it has a higher exciton binding energy, greater radiation hardness, is available in bulk and requires simpler crystal growth and processing technology. These advantages make it uniquely attractive for fabricating various electronic, optical and spintronic devices. However, the presence of high intrinsic n-type impurity concentration has hindered achievement of good quality p-type ZnO materials necessary for device fabrication. The objective of this project is to achieve high conductivity p-type ZnO films using delta doping by magnetron sputter deposition. Delta doping has successfully yielded enhanced p-type doping in many wide band gap semiconductors with similar p-type doping challenges. The p-type doping atoms will be spatially confined in a narrow layer, resulting in a two-dimensional doping density profile with a unique V-shaped potential well, which exceeds the solubility limit of the commonly used homogeneous doping. This project could lead to transformational outcomes as it will not only impact semiconductor device development, but also permit investigation of the basic science related to the fundamental limits of doping profile miniaturization.