The impact of interfacial Si contamination on GaN-on-GaN regrowth for high power vertical devices
Year: 2021
Type: article
Abstract: The development of gallium nitride (GaN) power devices requires a reliable selective-area doping process, which is difficult to achieve because of ongoing challenges associated with the required etch-then-regrow process. The presence of silicon (Si) impurities of unclear physical origin at the GaN regrowth interface has proven to be a major bottleneck. This paper investigates the origin of Si contamination at the epitaxial GaN-on-GaN interface and demonstrates an approach that markedly reduces its impact on device performance. An optimized dry-etching approach combined with UV-ozone and chemical etching is shown to greatly reduce the Si concentration levels at the regrowth interface, and a significant improvement in a reverse leakage current in vertical GaN-based p–n diodes is achieved.
Source: Applied Physics Letters
DOI: 10.1063/5.0049473
Institutions: Arizona State University, Iowa State University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: WIDE BANDGAP GAN SEMICONDUCTOR HAS UNIQUE MATERIAL PROPERTIES THAT PROMISE HIGH POWER AND HIGH FREQUENCY ELECTRONICS SYSTEMS. COMPARED TO CONVENTIONAL SI MATERIAL GAN HAS MUCH LARGER BANDGAP AND LOWER INTRINSIC CARRIER DENSITY WHICH WILL ALLOW FOR EFFICIENT ELECTRONIC DEVICES WORKING AT HIGH TEMPERATURES. COMPARED TO OTHER HIGH TEMPERATURE MATERIALS SUCH AS SIC GAN HAS MUCH HIGHER MOBILITY WHICH WILL LEAD TO ELECTRONIC DEVICE WITH MUCH HIGHER SPEED AND MICROSYSTEMS WITH HIGHER CLOCK FREQUENCY. IN THIS PROPOSAL WE PLAN TO DEMONSTRATE A GAN-BASED MICROPROCESSOR THAT CAN WORK EFFICIENTLY UNDER HIGH TEMPERATURE (E.G. >500 C) WHICH IS THE FIRST OF ITS KIND. FUNDAMENTAL STUDIES WILL BE PERFORMED ON THE HIGH TEMPERATURE PROPERTIES OF GAN DEVICES INCLUDING MATERIAL DEFECTS ELECTRON TRANSPORTS AND THERMAL STABILITIES AND THEIR IMPACTS ON THE PERFORMANCE AND RELIABILITIES OF GAN MICROPROCESSORS WILL BE DISCUSSED. AN INTERDISCIPLINARY APPROACH IS PROPOSED WHICH INCLUDES MATERIAL GROWTH AND CHARACTERIZATION TCAD-BASED DEVICE/ PROCESS SIMULATIONS MICROPROCESSOR CHIP FABRICATION AND COMPREHENSIVE HIGH TEMPERATURE CHARACTERIZATIONS. THE REALIZATION OF THIS MICROPROCESSOR REPRESENTS A POTENTIALLY DISRUPTIVE TECHNOLOGY THAT WILL ENABLE ELECTRONICS SYSTEM BASED ON WIDE BANDGAP GAN DEVICES WITH GREATER EFFICIENCY MUCH REDUCED SIZE AND WEIGHT AND HIGHER OPERATION TEMPERATURE ALL OF WHICH ARE HIGHLY DESIRABLE FOR VARIOUS NASA AND SPACE APPLICATIONS., G2897981719, ULTRA MATERIALS FOR A RESILIENT, SMART ELECTRICITY GRID, NNCI: Nanotechnology Collaborative Infrastructure Southwest (NCI-SW)
OpenAlex ID: W3169948844