Planar Wurtzite III-N Gunn Diodes for High Power Millimeter Wave and THz Electronics

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Abstract Title: Planar Wurtzite III-N Gunn Triodes for High Power Millimeter Wave and THz Electronics Nontechnical Description: The primary objective of the proposed research is to develop innovative high power III-nitride millimeter-wave and terahertz sources of electromagnetic radiation, filling a long-standing technology gap for robust, compact, solid-state devices capable of operating at room temperature. The transformative Gunn triodes proposed here will leverage many years of experience with III-nitride HEMT technologies, and focus on high-quality materials growth, fabrication, design, modeling and high-power high-speed III-nitride device physics research. Through the proposed research tasks, an entirely new architecture for room temperature solid state millimeter-wave and terahertz sources will be demonstrated for a host of diverse applications including wireless communications, automotive radar, remote sensing, medical imaging, concealed object detection, spectroscopy and inter-satellite transmissions. In education outreach activities, the program will enable a close collaboration between the PIs' groups and Georgia Tech's Center for Education Integrating Science, Mathematics and Computing to actively engage in K-12 education. The program will create online resources for the Georgia STEM Incubator initiatives for K-12 science course modules and help design online professional development curriculum units for teachers on green energy technologies and energy conservation related topics. Students from underrepresented groups will be involved in the research through Summer Undergraduate Research in Engineering/Science programs at Goergia Tech. The program will also host Georgia Intern Fellowship for high school S&T teachers for both continuing education and cultivation of the next-generation of the Science of Engineering education workforce. Technical Description: The successful completion of the proposed work shall result in the very first demonstration of a wurtzite III-nitride based Gunn-effect device. The basis of the proposed approach is the use of advanced metalorganic chemical vapor deposition (MOCVD) growth systems to produce GaN-based HEMT-like triode structures with atomically smooth polar interfaces on high-quality GaN substrates. Novel heterostructure Gunn triode designs and fabrication processing technologies will be explored and studied to facilitate successful demonstration of the proposed devices. A comprehensive understanding of the non-stationary and highly non-equilibrium carrier transport mechanisms under high electric-field conditions in these structures will be achieved through the application of state-of-the-art numerical simulation software based on full-band ensemble electro-thermal Monte Carlo solutions of the Boltzmann transport equation. Such calculations have recently provided valuable insight into the reasons why previous attempts to realize GaN-based Gunn effect devices have failed, and have facilitated the identification of a prototypical HEMT-like heterostructure in a triode configuration which addresses each of these shortcomings. The successful demonstration of the proposed III-N Gunn triodes will represent both a significant technological breakthrough in the field of III-N power electronic device research, providing a solid-state solution for the efficient generation of high-power millimeter-wave and terahertz signals at room temperature, as well as an advancement of fundamental science through the very first expression of the Gunn effect in the wurtzite III-nitride material system.