Vanadium ion implanted guard rings for high-voltage 4H-SiC Schottky rectifiers

Vanadium ion (51V+) implantation using a low dose in the range of 1012–1013 cm-2 was applied to form a high-resistivity guard ring for high-voltage 4H-SiC Schottky rectifiers. Breakdown voltages were successfully increased by the formation of a 51V+-implanted guard ring. To investigate the effects of the implanted guard ring, the width and depth were varied by the size of the mask pattern and the maximum implantation energy, respectively. With a 150 µm-wide and 0.5 µm-deep 51V+-implanted guard ring, a nearly ideal breakdown voltage of 1630 V was achieved using a 10 µm-thick epilayer.