Effect of Gate Pad Layout on Thermal Impedance of SiC-MOSFET

Abstract

In this paper, thermal impedance (Zth) of power modules which is assembled with a silicon carbide Schottky barrier diode (SiC-SBD) and metal oxide semiconductor field effect transistor (SiC-MOSFET) was measured and compared. SiC-MOSFETs had gate pads that accounted for 6% of the die size. SiC-MOSFETs had up to 55% higher thermal impedance and 13% higher steady-state thermal resistance compared to SiC-SBDs. Although the gate pad occupies only a small area in the device chip, it was found to have a significant difference on the thermal impedance of SiC power modules, especially in the short time region.