Macro and nanoscopic characteristics of SiC-SiO₂ interface roughness and leakage current through vacuum annealed thermally nitrided SiO₂ gate on 4H-SiC

10%-N2O nitrided SiO₂ gate on n-type 4H SiC has been used to investigate macro and nanoscopic characteristics of SiC-SiO₂ interface roughness and leakage current through the oxide. Non-contact mode atomic force microscope (AFM) and conductive AFM have been employed for the nanoscopic analyses, while macroscopic analyses have been performed by x-ray reflectivity and Semiconductor Parameter Analyser (SPA). From the nanoscopic analyses, it has found that the rougher the interface, the lower the leakage current. However, there is no relationship between the interface roughness obtained from nanoscopic measurement by AFM and leakage current density from macroscopic measurement by SPA.