2023/10/03 by Giuseppe Capasso, Mauro Zanuccoli, Andrea Natale Tallarico +2
Physics and Astronomy · Engineering · #GaN-based semiconductor devices and materials #Silicon Carbide Semiconductor Technologies #Semiconductor materials and devices
paper · pdf · doi:10.1109/ted.2023.3318865
This article presents an in-circuit approach to assess the long-term reliability of enhancement-mode GaN HEMTs. A synchronous buck converter conceived for the on-board transistors’ characterization is proposed. Here, high-side and low-side power transistors operate under realistic stress conditions, whereas their degradation is assessed by measuring, in-circuit, the full <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">I </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">V </tex-math></inline-formula> characteristics at prefixed stress times. Moreover, a long-term reliability analysis of commercial 80-V GaN HEMTs is reported. Threshold voltage and ON-state resistance degradation induced by the buck converter operation is investigated, as well as their dependencies on the input voltage, duty cycle, ambient temperature, and output current. Results highlight a clear difference compared to standard dc-stress and reveal a strong correlation between the degradation of the high-side transistor and the input voltage. On the contrary, the low-side transistor degradation is almost insensitive to the different operating regimes of the power converter.