The photon-stimulated desorption of ${\mathrm{H}}^{+}$ from cleaved Si(111) using photon energies near the Si $K$ excitation threshold is reported. The time dependence of the H surface segregation from the bulk following cleavage shows two or three sequential time regimes of growth kinetics suggesting multiple sequential hydride phase formations. Removal of the H from the H-saturated surface results in the subsequent observation of only the first time regime (which we interpret as being due to formation of a monohydride phase).

• Received 29 April 1982

DOI:https://doi.org/10.1103/PhysRevB.26.2292