Temperature dependence of on-resistance components in recessed p-Channel GaN MOSFETs

초록

The temperature-dependent operation of recessed enhancement-mode p-channel GaN MOSFETs has been investigated through detailed resistance component analysis. Unlike conventional semiconductor transistors, where carrier mobility degradation typically dominates at elevated temperatures, the p-GaN MOSFETs studied here exhibited a distinctly different behavior. The total on-resistance (RON) was decomposed into channel and contact contributions, revealing that the contact and access resistances (2RC, RS, and RD) decreased monotonically with increasing temperature while the MOS channel resistance (RMOS) exhibited a unique two-regime behavior. At lower temperatures, RMOS slightly increased, possibly reflecting enhanced phonon and surface-roughness scattering near the oxide/p-GaN interface. At higher temperatures, RMOS decreased, which may be associated with Coulomb screening and thermally activated carrier detrapping that mitigate interface-related transport limitations in the accumulation channel. To the best of our knowledge, this is the first report of the two-regime temperature dependence of the MOS channel resistance in recessed p-channel GaN MOSFETs. These findings indicate a distinct temperature-dependent transport behavior in p-GaN MOSFETs, highlighting the critical role of contact engineering and channel design. These insights provide essential guidelines for the development of thermally reliable p-GaN devices and the realization of high-performance complementary GaN power ICs. © 2026

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