Investigation into the On-Resistance Shift Phenomenon of 650V Commercial GaN Power Devices with Different Structures

The unique two-dimensional electron gas (2DEG) structure in GaN-on-Si planar GaN enables excellent performance, but it also brings negative effects such as current collapse, threshold voltage offset and on-resistance $(\boldsymbol{R}_{\mathbf{dson}})$ shift. This paper investigates the effects of voltage, temperature and switching mode (hard/soft switching) on the $\boldsymbol{R}_{\mathbf{dson}}$ of GaN power devices, specifically for 650V commercial GaN power devices with different structures from GaNsystems, Nexperia and Visic. This paper also presents a GaN on-resistance test platform to observe the $\boldsymbol{R}_{\mathbf{dson}}$ shift process within 10 hours. The results show that $\boldsymbol{R}_{\mathbf{dson}}$ shift is a common problem for all three GaN power devices under test. The degree of on-resistance shift is positively correlated with the drain voltage and negatively correlated with the junction temperature. In addition, soft switching can effectively suppress $\boldsymbol{R}_{\mathbf{dson}}$ shift by avoiding simultaneous high voltage and high current.