Radiation Effects in AlGaN/GaN HEMTs

• Published in: IEEE transactions on nuclear science Vol. 69; no. 5; p. 1
• Main Authors: Fleetwood, Daniel M., Zhang, En Xia, Schrimpf, Ronald D., Pantelides, Sokrates T.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 1/f noise; Aluminum gallium nitride; Aluminum gallium nitrides; Bias; Burnout; defects; Degradation; Dehydrogenation; Electric potential; Electronic devices; Energy levels; Fluence; gallium nitride; Gallium nitrides; HEMTs; High electron mobility transistors; hydrogen; Impurities; Irradiation; LF noise; MODFETs; Point defects; Protons; Radiation; Radiation effects; Semiconductor devices; Single Event Effects; Space applications; Transconductance; Voltage; Wide band gap semiconductors
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2022.3147143

An overview is presented of displacement damage (DD) effects, total-ionizing-dose (TID) effects, and single-event effects in AlGaN/GaN HEMTs. High-fluence proton-induced DD creates point defects and impurity complexes at fluences that are comparable to or higher than those encountered in space applications. Defect and impurity dehydrogenation also contributes significantly to the DD/TID response at fluences typical of realistic space environments. The bias applied during irradiation can affect the DD/TID response strongly. Bias-stress before irradiation can lead to enhanced proton-induced degradation of AlGaN/GaN HEMTs. Low-frequency noise measurements and density functional calculations provide insight into defect micro-structures and energy levels. GaN-based HEMTs can be quite vulnerable to single-event effects in space. Of particular concern is single-event burnout (SEB). The vulnerabilities of GaN-based devices to SEB at voltages below rated limits and significant device-to-device variations in SEB response lead to significant voltage derating for GaN-based power devices in space systems. Developing an improved understanding of the effects of defects and hydrogen on the radiation response of AlGaN/GaN HEMTs can improve the DD/TID response by reducing threshold-voltage shifts and transconductance degradation. Reducing defect densities may also reduce the variation in SEB response, enabling reliable device operation at higher voltages in future space systems.