Reduction of interface state density in SiC (0001) MOS structures by post-oxidation Ar annealing at high temperature

• Published in: AIP advances Vol. 7; no. 4; pp. 045008 - 045008-5
• Main Authors: Kobayashi, Takuma, Suda, Jun, Kimoto, Tsunenobu
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 01.04.2017; AIP Publishing LLC
• Subjects: Annealing; Conduction bands; Cooling rate; Density; High temperature; Nitric oxide; Oxidation; Reduction
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.4980024

We found that post-oxidation Ar annealing at high temperature is effective in reducing the interface state density (D it) near the conduction band edge (E C) of SiC (0001) MOS structures. The D it reduction effect is comparable to that of nitridation process (annealing in nitric oxide (NO)) which has been a standard in SiC MOS technologies, without introducing any foreign atoms into the interface/oxide. The generation of fast interface states, which have been pointed out as a problem of nitridation process, is suppressed in the case of Ar annealing. In the proposed method, the final D it values are mainly determined by the Ar annealing temperature rather than the initial oxidation temperature. The D it values are not sensitive to the cooling speed, which means that rapid cooling is not necessary in the proposed method.