C-Face Epitaxy for Enhanced SiC Device Performance: Insights from Schottky Barrier Diodes

This study focuses on analyzing the electrical performance and characteristics of Schottky Barrier Diodes (SBDs) on the carbon face (C-face) epitaxial layer. The C-face epitaxial layer is grown on monocrystalline 4H-SiC and has a thickness of ~ 11 μm. It displayed minimal surface roughness, with an R q of ~ 0.3 nm. The C-face termination epitaxy was examined using grazing-angle X-ray photoelectron spectroscopy (XPS) analysis. SBDs were fabricated using a Ti/Al metal stack. Schottky Barrier Height ( Φ B ) of about 1.2 eV was extracted from I - V measurements. Temperature-dependent I - V measurements demonstrated a forward voltage decrease as the temperature rises when the forward current is < 1 μA. However, for forward currents > 1 μA, the forward voltage increases with temperature. This rise in forward voltage could lead to a reduction in reverse recovery time and thus enhancing the switching speed. Additionally, the diode exhibits remarkable immunity to reverse leakage current up to 200 °C, surpassing the performance of the 6.5 kV JBS diode on Si-face 4H-SiC [1].