Electronic, Chemical and Structural Properties of Metamorphic III-V Compound Heterojunctions and Devices

这个FRG(重点研究小组)项目致力于解决变质材料科学问题--成分分级的松弛中间层，用于缓解衬底和所需异质结构之间的应变-III-V半导体异质结构以及变质III-V器件的设计和性能。目标是：了解变形和应变异质结构的生长、纳米级界面属性(电子、化学、结构)和整体材料属性之间的复杂相互关系，并利用这一理解来制造超越当前高速设备的新型变形设备。几个有代表性但相关的材料体系对设备技术和基础材料科学的进步产生了影响。跨学科团队由研究人员组成，他们结合了外延生长、表征、器件设计和制造方面的互补专业知识，以及具有共同兴趣的理论，探索和利用晶格不匹配异质结构的生长、界面特性、电子和结构特性以及器件特性之间的关系。核心活动包括：(1)开发新型阴离子基III-V复合梯度缓冲器，以扩展异质结的可能材料组合；(2)创建界面表征技术，提供关于在不同受控生长条件下形成的异质结的关键电子、化学和结构信息；(3)利用变质过渡层的灵活性，创建具有先进电子特征的新型器件结构；以及(4)开发基于原子组成和几何结构准确描述异质结带偏和深能级的理论方法。%该项目的一个重要影响是通过研究和教育的整合在教育和人力资源开发方面。FRG团队的多学科性质为学生提供了一个欣赏和学习研究过程的广阔视角的环境。每个学生的研究主题是高度相互依存的，这将提供一个初步的研究经验，促进他们未来职业生涯中团队合作的概念。主要研究人员之间重叠的兴趣和互补的技能将允许学生通过学习新技术和参与通常在导师活动之外的相关研究来扩大他们超出常态的经验。因此，通过所有学生FRG成员之间的自然师生交流，学生教育与研究相结合。应用于该项目的研究基础设施非常庞大，从材料生长到纳米级表征和先进器件制造和测试。因此，学生将接受最先进的方法培训，这些方法将成为他们未来职业生涯的基石，增强未来研究和教育的基础设施。该项目由MPS/DMR/EM和ENG/ECS/EPDT计划共同支持。*

This FRG (focused research group) project addresses materials science issues of metamorphic--compositionally-graded, relaxed interlayers used to relieve strain between a substrate and desired heterostructures-III-V semiconductor heterostructures and the design and performance of metamorphic III-V devices. Objectives are to: understand complex inter-relationships between growth, nano-scale interface properties (electronic, chemical, structural), and bulk material properties for metamorphic and strained heterostructures and to use this understanding to generate novel, metamorphic devices that extend beyond current high speed devices. Several representative but related material systems that impact advances in device technology and in fundamental materials science are considered. The interdisciplinary team consists of researchers who combine complementary expertise in epitaxial growth, characterization, device design and fabrication, and theory with a shared interest to explore and exploit the relationships between growth, interface properties, electronic and structural properties, and device characteristics for lattice-mismatched heterostructures. Core activities include: (1) developing novel, anion-based III-V compound graded buffers that expand the possible material combinations for heterojunctions; (2) creating interface characterization techniques that provide key electronic, chemical, and structural information on heterojunctions formed under different controlled growth conditions; (3) using the flexibility of metamorphic transition layers to create novel device structures with advanced electronic features; and (4) developing theoretical methods that accurately describe heterojunction band offsets and deep levels based on atomic composition and geometrical structure. %%% An important impact of the project is in education and human resource development through the integration of research and education. The multi-disciplinary nature of the FRG team provides an environment where students can appreciate and learn a broad perspective on the research process. Individual student research topics are highly interdependent, which will provide an initial research experience that promotes the notion of teaming in their future careers. Overlapping interests with complementary skills among the principal investigators will allow students to broaden their experience beyond the norm by learning new techniques and participating in related research normally outside their advisor's activities. Thus, student education is integrated with research through a natural student-teacher exchange amongst all student FRG members. The research infrastructure being applied to this project is substantial, ranging from materials growth, to nano-scale characterization and advanced device fabrication and testing. Hence, students will be trained in state-of-the-art methods that will be cornerstones for their future careers that enhance the future infrastructure for research and education. The project is co-supported by the MPS/DMR/EM and ENG/ECS/EPDT Programs.***