Improvement of interface properties in SiC(0001) MOS structures by plasma nitridation of SiC surface followed by SiO₂ deposition and CO₂ annealing

Abstract

Abstract Although nitridation passivates defects at the SiO 2 /SiC interface, avoiding the introduction of nitrogen atoms into SiO 2 is crucial for reliability. This paper presents a method to selectively introduce nitrogen at the SiC-side of the interface. The method comprises the following steps: (i) plasma nitridation of the SiC surface, (ii) sputter deposition of SiO 2 , and (iii) annealing in a CO 2 ambient. Significantly low D it values of about 1 × 10 11 cm −2 eV −1 were obtained near the conduction band edge of SiC. Furthermore, the resulting interface properties were hardly degraded by excimer ultraviolet light irradiation, indicating better stability compared with a NO-nitrided sample.