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

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

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. ***