Schottky Barrier Characteristic Analysis on 4H-SiC Schottky Barrier Diodes With Heavy Ion-Induced Degradation

Abstract

Leakage current of 1200-V 4H-SiC Schottky barrier diodes (SBDs) with different structures increased by various degrees after heavy-ion exposure. By taking <inline-formula> <tex-math notation="LaTeX">${I}$ </tex-math></inline-formula>&#x2013;<inline-formula> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> measurements in a range of 298 to 448 K, the voltage dependence of saturation current (<inline-formula> <tex-math notation="LaTeX">$I_{0}$ </tex-math></inline-formula>), barrier height (<inline-formula> <tex-math notation="LaTeX">$\phi _{B0}$ </tex-math></inline-formula>), and ideality factor (<inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula>) were obtained. The dependence of these parameters with temperature illustrates the Gaussian distribution of barrier height. The inhomogeneity of the Schottky barrier height (SBH) distribution was successfully described using a modified thermionic emission (TE) model with Gaussian distribution, and the average barrier height (<inline-formula> <tex-math notation="LaTeX">$\bar {\phi }_{B0}$ </tex-math></inline-formula>) was gained. The results show that the barrier height distribution of all SBDs remain unchanged after the irradiation which means heavy-ion exposure did not affect the Schottky barrier.