Improvement of SiO<sub>2</sub>/4H-SiC(0001) Interface Properties by H<sub>2</sub> and Ar Mixture Gas Treatment Prior to SiO<sub>2</sub> Deposition

Abstract

We investigated the impact of high-temperature H2/Ar mixture gas treatment of 4H-SiC(0001) surfaces before SiO2 deposition on the electrical properties of SiO2/SiC interfaces. Physical characterizations revealed that the SiC surface treated by the H2/Ar mixture gas exhibited a (√3×√3)R30° structure composed of Si-O bonds, indicating that a well-ordered and stable silicate adlayer was formed by the treatment to passivate SiC(0001) surface. Electrical defects at the CVD-grown SiO2/SiC interface was significantly reduced by the treatment. Consequently, a peak electron mobility in SiC-MOSFETs with the deposited gate oxides was enhanced to 24.9 cm2/Vs.