Formation of high-quality SiC(0001)/SiO₂ structures by excluding oxidation process with H₂ etching before SiO₂ deposition and high-temperature N₂ annealing

Abstract

We formed SiC/SiO2 structures by various procedures that excluded an oxidation process. We found that a SiC/SiO2 interface with a low interface state density near the conduction band edge of SiC (D it ∼ 4 × 1010 cm−2 eV−1 at E c −0.2 eV) is obtained for a fabrication process consisting of H2 etching of the SiC surface, SiO2 deposition, and high-temperature N2 annealing. D it is rather high without H2 etching, indicating that etching before SiO2 deposition plays a significant role in reducing D it. The key to obtaining low D it may be the removal of oxidation-induced defects near the SiC surface.

Tailoring Structural, Chemical, and Photocatalytic Properties of ZnO@β-SiC Composites: The Effect of Annealing Temperature and Environment

“…The vacuum-annealed FTIR results are shown in Figure , demonstrating the absence of SiO 2 (∼1097 cm –1 ) in both β-SiC and ZnO@β-SiC composite. Considering the air annealing results in Figure , it is clear that SiO 2 cannot be formed in β-SiC without air, in good agreement with the results of Tachiki et al Given the findings of Figures and , the emergence of the zinc silicate phase in Figure can only be explained by the production of SiO 2 via oxidizing β-SiC in air from 900 °C and the subsequent chemical reaction at the ZnO/β-SiC interface.…”

“…The evolution of the silanone group (pointed by a vertical red dashed line) at the SiC/SiO 2 interface with a weak feature ( ∼1305 cm –1 ) from S-7A is clearly visible besides the observation of the TO (∼780 cm –1 ) and LO (∼820 cm –1 ) modes of SiC . The key finding is that a peak at ∼1097 cm –1 is found to be more prominent from 900 °C, which is assigned to be related to the formation of SiO 2 in SiC. − To justify the involvement of the surrounding environment in surface oxidation, both β-SiC and the ZnO@β-SiC composite were also annealed in vacuum at 900 °C for 90 min in a horizontal split furnace (base pressure ∼2 × 10 –6 mbar) with a heating/cooling rate of 4 °C/min, called S-9VA and ZS-9VA, respectively. The vacuum-annealed FTIR results are shown in Figure , demonstrating the absence of SiO 2 (∼1097 cm –1 ) in both β-SiC and ZnO@β-SiC composite.…”

High-voltage SiC power devices for improved energy efficiency

“…14 (c) (Process B), a SiO 2 film is directly deposited on the SiC surface by chemical vapor deposition (CVD). 76 ) In either case, without H 2 etching of the SiC surface at 1300–1350 ℃ prior to thin film deposition (Si or SiO 2 ) as well as interface nitridation after oxide formation, the interface state density was even higher than that by the conventional process shown in Fig. 14 (a).…”

Simultaneous Interface Defect Density and Differential Capacitance Imaging by Time-Resolved Scanning Nonlinear Dielectric Microscopy

“…In this context, reducing high interface defect density (D it ) at SiO 2 /SiC interfaces has been under ongoing study to reap benefits from the superior material properties of SiC as well as eliminating bulk defects [1]. Tachiki et al have recently established a novel procedure for the formation of the SiO 2 layer and achieved drastic reduction of D it [2]. As a result, achievable channel mobility has been improved twofold but still one order magnitude lower than expected [3].…”