Self-Heating in GaN Transistors Designed for High-Power Operation

Jan Kuzmik, Milan Tapajna, Lukas Valik, Marian Molnar, Daniel Donoval, Clement Fleury, Dionyz Pogany, Gottfried Strasser, Oliver Hilt, Frank Brunner, Joachim Wurfl
2014 IEEE Transactions on Electron Devices  
DC and transient self-heating effects are investigated in normally off AlGaN/GaN transistors designed for a highpower operation. Electrical and optical methods are combined with thermal simulations; 2-µs-long voltage pulses dissipating about 4.5 W/mm are applied on four different transistor structures combining GaN or AlGaN buffer on an n-type SiC substrate with or without Ar implantation. Transistors with only 5% Al mass fraction in the buffer show almost a threefold increase in the transient
more » ... e in the transient self-heating if compared with devices on the GaN buffer. On the other hand, 2-µs-long pulses were found not to be long enough for the Ar-implanted SiC substrate to influence the device self-heating unless AlGaN composition changes. In the dc mode, however, both the buffer composition and Ar implantation significantly influence the self-heating effect with the highest temperature rise for the transistor having the AlGaN buffer grown on the Ar-implanted SiC. We point on possible tradeoffs between the transistor high-power design and the device thermal resistance.
doi:10.1109/ted.2014.2350516 fatcat:rcmd2p7xxjdurbtg7xbqx5r5nq