Enhanced photon-induced carrier density in silicon-on-insulator via surface recombination suppression for increasing plasma dispersion effect

The authors studied enhancement of photon-induced carrier density in silicon-on-insulator (SOI) by suppressing surface recombination. Through applying electric field at the top silicon surface or at the Si/SiO(2) interface, either electrons or holes are depleted near the interface, reducing the possibility of recombination. We examined enhanced photon-induced carrier density depending on the thickness of the SOI layer and the polarity of the applied field. The results show that the enhanced carrier density is prominent for thin SOI and increases with applied voltage. The effective photon-induced carrier density is magnified by three times with surface bias simultaneously at the top and bottom interfaces of SOI. The corresponding plasma dispersion effect is also estimated. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3106527]