Trapping-mediated chemisorption of disilane on Si(100)-2×1

摘要: Disilane adsorption probabilities have been measured on Si(100)-2×1 over a wide range of incident kinetic energies, angles, and surface temperatures using supersonic molecular beam techniques. The trapping-mediated chemisorption mechanism is shown to be the dominant pathway under conditions investigated. first step in such mechanism, namely trapping into physical well, has studied directly via measurements at temperature 77 K. As expected, probability drops with increasing energy, but nearly 50% molecules trap 1 eV indicating that quite efficient translational energies. Chemisorption values higher are fit simple model can used predict conditions. Measurements 500 K independent angle energies 0.75 below. However, decrease incidence 0.6 above. This unusual effect discussed terms scattering during parallel momentum accommodation. In order investigate hydrogen formed as result disilane decomposition, were function monohydride coverage well. On monohydride-saturated found lower than bare surface, most likely due decreased binding energy compared surface. Also, varies linearly between bare-surface values. other hand, dependence follow second-order scheme based occurring two vacant sites.