Influence of PECVD of SiO2 Passivation Layers on 4H-SiC Schottky Rectifiers

The effect of the deposition conditions of plasma enhanced chemical vapor deposition (PECVD) SiO 2 layers on the electrical properties of 4H-SiC Schottky rectifiers is reported. In a SiH 4 /N 2 O plasma chemistry, the reverse breakdown voltage, forward turn-on voltage, and on-state resistance of the rectifiers all increase with increasing plasma power and SiH 4 content and decreasing deposition pressure. The maximum changes in all these parameters were ≤20% over a broad range of plasma conditions and show that 4H-SiC is relatively resistant to changes induced by the ion bombardment and high atomic hydrogen flux present during PECVD of dielectrics for surface passivation.