Improvement of SiO_2/4H-SiC(0001) Interface Properties by H_2 and Ar Mixture Gas Treatment Prior to SiO_2 Deposition

摘要

We investigated the impact of high-temperature Hsub2/sub/Ar mixture gas treatment of 4H-SiC(0001) surfaces before SiOsub2/sub deposition on the electrical properties of SiOsub2/sub/SiC interfaces. Physical characterizations revealed that the SiC surface treated by the Hsub2/sub/Ar mixture gas exhibited a (√3×√3)iR/i30° 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 SiOsub2/sub/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 cmsup2/sup/Vs.