[18p-P14-1~19] 15.6 Group IV Compound Semiconductors (SiC)

[18p-P14-10] Atomic Structure Analysis of SiO₂/SiC Interfaces by X-ray Absorption Spectroscopy

〇Noritake Isomura¹, Satoru Kosaka¹, Keita Kataoka¹, Yukihiko Watanabe¹, Yasuji Kimoto¹ (1.Toyota CRDL)

Keywords:SiC-MOSFET, XAFS, interface structure

Extended X-ray absorption fine structure (EXAFS) spectroscopy is demonstrated to measure the fine atomic structure of SiO₂–SiC interfaces. The SiC-side of the interface can be measured by fabricating thin SiO₂ films and using SiC-selective EXAFS measurements. Fourier transforms of the oscillations of the EXAFS spectra correspond to radial-structure functions and reveal a new peak of the first nearest neighbor of Si for m-face SiC, which does not appear in measurements of the Si-face. This finding suggests that the m-face interface could include a structure with shorter Si–C distances. Numerical calculations provide additional support for this finding.