Efficient P-Type Doping and the Role of Defects in Limiting Acceptor Activation in III-Nitrides

本研究的目的是在氮化镓（GaN）中获得高导电性的p型层。实现这一目标的方法是识别限制氮化镓中p型传导的缺陷，然后通过使用一种新的超高速微波退火技术降低这些缺陷的密度。智力优势：将通过在几种控制条件下制备的未掺杂和受体掺杂GaN层进行光致发光、阴极发光、霍尔和二次离子质谱测量，研究p型原位和离子注入GaN层中负责受体水平和几种未识别的自补偿深层供体水平的缺陷和缺陷复合物。本文研究的受体掺杂材料包括原位掺杂层和生长后离子注入掺杂层。原位氮化层和离子注入氮化层将采用一种新的超快高温（1400C）微波退火步骤来修复植入损伤和淬灭可能影响原位氮化层和离子注入氮化层中受体活化的天然缺陷。在退火过程中，GaN层将被石墨或AlN帽保护。有意引入的受体掺杂剂将是Mg和be。更广泛的影响：这项工作的成功成果可能对国家安全感兴趣的大功率、微波、高温和光电子器件的发展产生深远的影响。这项工作将与几个联邦实验室合作完成。本科生和高中生将参与该项目。建议工作的结果将包括在一个专题研究生课程。

The objective of this research is obtaining highly conductive p-type layers in gallim nitride (GaN). The approach for accomplishing this objective is identifying defects limiting the p-type conduction in GaN and then reducing the density of these defects by using a novel ultra high-speed microwave annealing technique. Intellectual Merit: The defects and the defect complexes responsible for acceptor levels and several unidentified self-compensating deep donor levels in p-type in-situ and ion-implantation doped GaN epilayers will be investigated by performing photoluminescence, cathodoluminescence, Hall and secondary-ion-mass-spectrometry measurements on undoped and acceptor doped GaN layers prepared under several controlling conditions. Acceptor doped materials that will be studied in this work include both in-situ doped epilayers and post-growth ion-implantation doped layers. The in-situ and ion-implantation doped nitride layers will be subjected to a new ultra-fast high-temperature (1400C) microwave annealing step to repair the implant damage and to quench the native defects, which may be affecting the acceptor activation in both in-situ and ion-implantation doped layers. During annealing, the GaN layer will be protected by a graphite or an AlN cap. The intentionally introduced acceptor dopants will be Mg and Be. Broader Impact: Successful results of this work may have profound effect on the development of high-power, microwave, high-temperature and optoelectronic devices, which are of interest for national security. This work will be done in collaboration with several federal laboratories. Undergraduate and high-school students will be involved in the project. Results of the proposed work will be included in a special topics graduate course.