Vibrational Studies of CH3I on Si(100)-(2x1): Adsorption and Decomposition of theMethyl Species

摘要

The dissociative adsorption of CH3I to adsorbed CHI and I on a clean Si(100)-(2x1) surface has been studied-by high resolution electron energy loss spectroscopy (HREELS), temperature programmed desorption (TPD) and Auger electron spectroscopy (AES). The thermal stability-of CH3(a)-to 600 has been witnessed spectroscopically. At higher temperatures, Ch3(a) decomposes to CH(a), possibly via the production of intermediate =CH2(a) species. The CH(a) species is stable to 800 K. HREELS and TPD show that-following CH3I dissociative adsorption at 100 K, a multilayer of undissociated CH3I is condensed on the substrate. Upon heating this condensed overlayer is desorbed with a peak temperature of 225 K. H2 and I desorption occur near 785 K, leaving adsorbed carbon on the Si(100) surface. Methyl Carbon Silicon Methyl Iodide.