Silicon surface kinetics studied using laser-induced thermal desorption

Abstract

Laser induced thermal desorption (LITD) has emerged as a powerful time-dependent probe of surface processes. The ability of LITD to desorb silicon-containing species from Si(l1l)7x7 has been employed to study the decomposition of H₂0 and NH₃ on Si(l11)7x7. These LITD studies on Si(111)7x7 assumed that the silicon-containing species were derived from surface reaction intermediates. This assumption was recently tested by transmission FTIR investigations of H20 and NH₃ decomposition on high surface area porous silicon surfaces. The LITD and FTIR results were compared for the thermal stability of the SiOH surface species during H₂O decomposition and the SiNH₂ surface species during NH₃ decomposition. The good agreement between the LITD and the FTIR investigations indicated that the silicon containing LITD species correspond to silicon surface reaction intermediates.