Investigation of interface state density near conduction band edge of 4H-SiC MOSFET based on inversion capacitance and drain-current characteristics

Abstract

We propose a simple method to evaluate interface state density (D it ) near the conduction band edge of 4H-SiC MOSFETs, which is difficult to observe by conventional methods although it degrades device characteristics. We focus on a capacitance-voltage method with inversion capacitance, applying high voltage to a set reference point where almost all traps are occupied and sweeping downward gradually. Our method is applicable for mass production because of the convenient sequence. We also demonstrate that the device characteristics calculated based on the extracted D it are in good agreement with the measured characteristics.

Electrically Active Defects in SiC Power MOSFETs

“…Numerous electrical characterization techniques, which were initially developed to characterize the Si-base MOS capacitors and MOSFETs, have been adopted for electrical characterization of the SiC devices. Since the interface traps are the dominant defects in Si devices, these conventional techniques are suitable for the defects with energy levels corresponding to the sub-threshold gate voltages (V G < V T ) in SiC devices [32][33][34][35].…”