The impact of surface morphology on C- and Si-face 4H-SiC Schottky barrier diodes

Abstract: The goal of this research is to investigate the correlation of reverse characteristics of Schottky barrier diodes (SBDs) and surface morphological defects on 4° (off-axis) carbon (C) face, 4° and 8° silicon (Si) face 4H-SiC. Different dimensions of SBDs with boron-implanted edge terminations are fabricated on 4° C-face, 4° and 8° Si-face 4H-SiC samples. The ideality factor for these three samples is about 1.1. Average breakdown voltages of 4° Si-face 4H-SiC SBDs are higher than the other two samples, particularly for large size SBDs. Breakdown voltages of 1500 and 2000μm 4° Si-face SBDs can reach over 1000V. This value is about two times higher than the other two samples, though the root-mean-square (RMS) roughness of 4° Si-face samples obtained from atomic force microscopy (AFM) is 3.5nm. The yield of 1500 and 2000μm 4° Si-face 4H-SiC SBDs with a breakdown voltage over 1000V is more than 50%, much higher than the other two samples. [Copyright &y& Elsevier]