[18a-E303-1~12] 13.1 Fundamental properties, surface and interface, and simulations of Si related materials

[18a-E303-6] A study on mechanisms of laser THz emission at MOS interface
- Separation of the surface electric field and the photo-Dember effect -

〇Tatsuhiko Nishimura¹, Hidetoshi Nakanishi¹, Iwao Kawayama², Masayoshi Tonouchi², Takuji Hosoi³, Takayoshi Shimura³, Heiji Watanabe³ (1.SCREEN, 2.ILE, Osaka Univ., 3.Graduate School of Eng., Osaka Univ.)

Keywords:MOS interface, THz wave, surface electric field

Laser Terahertz Emission Microscope (LTEM) enables to evaluate the electric field at the MOS interface. On the other hand, when the band bending is close to the flat band conditions, THz emission by the electric field at the interface is weak. Consequently, it is necessary to consider the photo-Dember effect, in which THz waves are generated owing to the different mobilities of electrons and holes excited at the surface. Our results suggest that this method of separating the surface electric field and the photo-Dember effect can improve the accuracy of LTEM measurement, and LTEM can contribute more as a useful evaluation technique for characterizing various interfaces including MOS interface.