The absolute sticking probability of NH3 molecules on Si(100) surface was measured using a NH3 molecular beam. Also taking into account the measured angular distribution of the scattered NH3 molecules, it is concluded that the adsorption of NH3 follows a trapping-mediated mechanism. From the dependence of the initial sticking probability on the sample temperature, the difference between the activation energies for desorption and chemisorption from a precursor state, (Edes-Ead), was estimated. The coverage dependence of the sticking probability, s(Θ), was also measured. From the sample temperature dependence of s(Θ), parameters for the migration of the NH3 precursor were derived using the Kisliuk model. The kinetics of the adsorption of NH3 on the Si(100) is discussed on the basis of this model.
- Adsorption kinetics
- Low index single crystal surfaces
- Molecule-solid scattering and diffraction - Inelastic
- Single crystal surfaces