Surface Fermi level position of hydrogen passivated Si(111) surfaces

Core and valence band photoemission data of hydrogen passivated Si(111):H surfaces yield surface Fermi level positions that are indicative of a near‐surface depletion layer for n‐ as well as p‐type samples. The bulk Fermi level positions are attained after annealing at ∼400 °C. These observations are explained in terms of a hydrogen induced passivation of donors and acceptors in a surface layer of the order of a μm as a result of the wet‐chemical etching procedure.