Adsorption dynamics of bifunctional molecules: Allyl methyl ether on Si(001).

The reaction dynamics of allyl methyl ether (AME) on Si(001) was studied by means of molecular beam techniques. The reaction of this bifunctional molecule comprising an ether and an alkene group was found to proceed via an intermediate state as deduced from the temperature dependence of the initial sticking probability s. At constant surface temperature T, s decreases continuously with increasing kinetic energy E, indicating a non-activated adsorption channel. Qualitatively and quantitatively, the energy dependence is almost identical to the adsorption dynamics of diethyl ether on Si(001). We attribute this to a similar nature of the intermediate state, which largely determines the adsorption dynamics. In consequence, this indicates a predominant role of the ether group and a minor influence of the C=C double bond on the adsorption dynamics of AME on Si(001).