FTIR STUDIES REVEAL THAT SILICON-CONTAINING LASER-INDUCED DESORPTION PRODUCTS ARE SURFACE-REACTION INTERMEDIATES

Silicon-containing laser-induced desorption (LID) products such as SiOH and SiNH2 have been observed from Si(111) 7 x 7 surfaces exposed to H2O and NH3. Assuming that the LID species were derived from surface reaction intermediates, these LID products were employed to examine the thermal stability of the SiOH and SiNH2 surface species. Fourier transform infrared (FTIR) transmission spectroscopy was recently utilized to monitor the decomposition of SiOH and SiNH2 surface species following the dissociative adsorption of H2O and NH3 on porous silicon surfaces. The FTIR results on porous silicon surfaces were in excellent agreement with the previous LID studies on Si(111) 7 x 7. The correspondence between the FTIR and LID investigations indicates that silicon-containing LID products are derived from silicon surface reaction intermediates.