Determination of the energy level of boron induced charge traps in Si/SiO$_{2}$ systems by second harmonic generation

Interfacial charge traps were characterized using second harmonic generation (SHG) in highly boron-doped Si/SiO$_{2}$ systems. We propose the presence of B$^{-}$ and B$^{+}$ ions in Si substrate and SiO$_{2}$ respectively across the interface [1]. A two color pump-probe SHG experiment was performed to determine the energy level of the B$^{+}$ ion in the oxide. A threshold wavelength of 475 nm (2.61 eV) was found for single photon excitation of electrons from the Si valence band to fill B$^{+}$ charge traps in SiO$_{2}$ [2]. This work was supported in part by DOE. \\[4pt] [1] H. Park and Y. Xu J. Qi, K. Varga, S. M. Weiss, B. R. Rogers, G. L\"upke, N. Tolk, Appl. Phys. Lett. 95, 062102 (2009). \\[0pt] [2] To be published.