Interface Trap Effects on the Output Characteristics of GaN Schottky Barrier MOSFET

초록

We analyzed the effects of the interface trap on the output characteristics of an inversion mode n-channel GaN Schottky barrier (SB)-MOSFET based on the Nit distribution using TCAD simulation. As interface trap number density (Nit) increased, the threshold voltage increased while the drain current density decreased. Under N<inf>it</inf>=5.0×1010 cm-2 condition, the threshold voltage was 3.2 V for V<inf>DS</inf>=1 V, and the drain current density reduced to 2.4 mA/mm relative to the non-trap condition. Regardless of the Nit distribution type, there was an increase in the subthreshold swing (SS) following an increase in N<inf>it</inf>. Under U-shaped Nit distribution, it was confirmed that the SS varied depending on the gate voltage. The interface fixed charge (Q<inf>f</inf>) caused an shift in the threshold voltage and increased the off-state current collectively with the surface trap. In summary, GaN SB-MOSFET can be a building block for high power UV optoelectronic circuit provided the surface state is significantly reduced. © 2022, Korean Sensors Society. All rights reserved.

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