Optical second harmonic generation as a probe for internal electric fields at the Si/SiO₂ interface

Date
2005
Journal Title
Journal ISSN
Volume Title
Publisher
Academy of Science for South Africa
Abstract
The second harmonic signal generated in native Si/SiO₂ interfaces using femtosecond laser pulses (80 ± 5 fs, 10.5 nJ, 1.59 eV) is time dependent. The temporal evolution of the electric field-induced second harmonic signal (EFISH) shows a steady incline and subsequent saturation for incident laser peak intensities below ∼45 GW/cm2 due to electron injection and trapping as well as defect generation in the SiO₂ layer. We used second harmonic generation imaging to visualize defect sample areas. In contrast, a drastically different behaviour of the time-dependent SH response of Si/SiO₂ interfaces was observed for peak intensities above ∼45 GW/cm2. The SH signal rose to a maximum and showed a subsequent decline over many minutes. We suggest hole injection into the ultra-thin SiO₂ layer as an interpretation of this observation.
Description
CITATION: Scheidt, T., Rohwer, E. G. & Von Bergmann, H. M. 2005. Optical second harmonic generation as a probe for internal electric fields at the Si/SiO₂ interface. South African Journal of Science, 101(1-2):91-92.
The original publication is available at https://journals.co.za
Keywords
Electric fields, Second harmonic generation, Lasers
Citation
Scheidt, T., Rohwer, E. G. & Von Bergmann, H. M. 2005. Optical second harmonic generation as a probe for internal electric fields at the Si/SiO₂ interface. South African Journal of Science, 101(1-2):91-92