Effect of hydrogen treatment on 4H-SiC Schottky barrier diodes

Abstract

In this letter, 4H-SiC Schottky barrier diodes (SBDs) with Ti Schottky metal have been subjected to hydrogen treatment in a confined environment of 4 % H2 and 96 % N2 at 150 °C. The effect of hydrogen treatment on the SBDs electrical characteristics has been investigated by technical computer-aided design simulation (TCAD) and power device analyzer curve tracer. The change of electrical parameters of SBDs measured after hydrogen treatment is studied in detail, and the related degradation mechanism is discussed. It was found that hydrogen treatment affected both the interface region and bulk region of SiC SBDs. After hydrogen treatment, the Schottky barrier increases slightly, the ideal factor (n) decreases slightly, and the interfacial state density (Dit) decreases. Hydrogen treatment resulted in a slight reduction in specific on-resistance (Ron-sp), which was attributed to the diffusion of H in SBDs. Through TCAD simulation, it is determined that the diffusion of H in the body diode of SBDs is the main reason for the degradation of high forward current and high reverse voltage characteristics.