Investigation of Power Cycling Degradation on the Dynamic ON-Resistance of HD-GITs

As promising candidates for high-performance power system applications, gallium nitride high electron mobility transistors (GaN HEMTs) have received a lot of attention from the market. However, reliability issues, particularly the dynamic on-resistance (dR$_{\text{DS(ON)}}$), also known as the current collapse effect, severely limit the promotion and application of GaN HEMTs. This article investigates and compares the dR$_{\text{DS(ON)}}$ under various power cycle aging conditions for hybrid drain-embedded gate injection transistors (HD-GITs), which serve as representative devices of GaN HEMTs. For the purpose of this, HD-GITs are prepared using power cycling tests, and a voltage clamping circuit is employed to accurately measure the dR$_{\text{DS(ON)}}$ during the switching applications in both the double-pulse test and the multipulse test. Experimental results demonstrate that, under certain conditions, the dR$_{\text{DS(ON)}}$ of the device deteriorates as it ages. Furthermore, the primary mechanisms responsible for the deterioration of dR$_{\text{DS(ON)}}$ characteristics under different aging states are discussed based on systematic electrical test results and reasonable inference. The finds are of great significance for guiding the design, manufacture, and application of GaN devices.