| AVS 54th International Symposium | |
| Electronic Materials and Processing | Thursday Sessions |
| Session EM-ThP |
| Session: | Electronic Materials and Processing Poster Session |
| Presenter: | C. Jeon, Sungkyunkwan University, Republic of Korea |
| Authors: | C. Jeon, Sungkyunkwan University, Republic of Korea J.H. Nam, Sungkyunkwan University, Republic of Korea W. Song, Sungkyunkwan University, Republic of Korea D.H. Oh, Sungkyunkwan University, Republic of Korea J.R. Ahn, Sungkyunkwan University, Republic of Korea C.-Y. Park, Sungkyunkwan University, Republic of Korea M.-C. Jung, Pohang Accelerator Laboratory, Republic of Korea H.J. Shin, Pohang Accelerator Laboratory, Republic of Korea Y.H. Han, Korea Atomic Energy Research Institute, Republic of Korea B.C. Lee, Korea Atomic Energy Research Institute, Republic of Korea |
| Correspondent: | Click to Email |
Among wide-band gap semiconductors, SiC has attracted interests in part because a stable native oxide SiO2 can be grown only on SiC. However, metal-oxide-semiconductor field effect transistors (MOSFETs) based on SiC have shown lower electric performance than expected from bulk SiC properties.1 The low electrical performance has been known to be related to defects at the SiO2/SiC interface. The defects produce fixed charges and interface trap states lowering electric performance. Several experiments using x-ray photoelectron spectroscopy have shown that the defects are Si suboxides (Si3+, Si2+, and Si1+) and Si oxycarbides (Si-C-O).2,3 Therefore, the reduction of defect density at the SiO2/SiC interface is one of crucial issues for device applications of the promising wide-band gap SiC. In this study, 1 MeV electron beam was irradiated on a SiO2/SiC wafer at room temperature and ambient condition to reduce the defect density at a SiO2/SiC interface, where a native SiO2 film with a thickness below 1 nm was naturally grown on a 6H-SiC(0001) wafer in air. The effect of the irradiation on the SiO2/SiC interface was investigated schematically by using synchrotron radiation scanning photoelectron microscopy with various incident photon energies (hν's). This makes it possible to measure spatially-resolved core-level spectra along directions parallel and perpendicular to a surface. Spatially-resolved Si 2p spectra show that 1 MeV electron beam irradiation reduces inevitable defects, Si suboxides (Si3+, Si2+, and Si1+) and Si oxycarbides (Si-O-C), at the SiO2/SiC interface with an ultrathin SiO2 film leaving an abrupt SiO2/SiC interface. It is meaningful that the defect reduction by the irradiation succeeds at room temperature and ambient condition. Therefore, MeV electron beam irradiation is a promising method in producing a high quality SiO2 and an abrupt SiO2/SiC interface.
1 Silicon carbide, A Review of Fundamental Questions and Applications to Current Device Technology, edited by W. J. Choyke, H. M. Matsunami, and G. Pensl (Akademie, Berlin, 1998), Vol. I and II.
2 F. Amy, P. Soukiassian, Y. K. Hwu, and C. Brylinski, Phys. Rev. B 65, 165323 (2002).
3 C. Virojanadara and L. I. Johansson, Phys. Rev. B 71, 195335 (2005).