Interaction of atomic hydrogen with a Ge(111) surface: low-energy electrondiffraction and surface Raman studies

We report the preparation and characterization of a sufficiently ordered Ge (lll)-1 x 1:H surface by prolonged hydrogenation of Ge(1 1 1)-c(2 x 8) at e levated temperatures. For both annealed and sputtered/annealed c(2 x 8) sur faces, a (1 x 1)pattern with distinct primary-order spots was observed by l ow-energy electron diffraction (LEED) after extensive hydrogenation treatme nt. We demonstrated that a surface Raman spectroscopic method based on pola rization effects can be used successfully to characterize such a prepared G e(lll)-1 x 1:H surface, which is flat enough to yield a single prominent pe ak of the monohydride GeH stretch. The possible mechanism for surface smoot hing by atomic hydrogen is also discussed. The smoothness of this surface m akes various spectroscopic characterization methods feasible. (C) 2000 Else vier Science B.V. All rights reserved.