Light-induced reversible conductivity changes in silicon-on-insulator nanowires

Silicon-on-insulator (SOI) samples are preferred for extention of the metal-oxide-silicon technology. Here, we report a reversible change in electrical conductivity in dark conditions of a 20-nm-thick SOI layer, induced by illumination. In spite of some similarities with the Staebler-Wronski effect in hydrogenated amorphous silicon, we point out important differences such as the crystalline nature of our silicon film, the lack of hydrogen and a much shorter relaxation time at ambient temperature. This time can even be reduced by application of a vertical electric field. We suggest that interface traps play a major role in this mechanism. Finally, we noticed a conductivity change between ambient light and dark conditions. (C) 2004 American Institute of Physics.