Silver-induced 3 x 3 phase on 6H-SiC(0001) root 3 x root 3 surface

The processes of structural and morphological change of a 6H-SiC(0001)root 3 x root 3 surface induced by Ag deposition and annealing have been studied by scanning tunneling microscopy (STM). A surface phase with 3 x 3 periodi city was found for Ag adsorption onto the root 3 x root 3 surface at 500 de grees C. STM images of this surface revealed one round protrusion per 3 x 3 unit cell in the empty state, and this round protrusion demonstrated a tri mer like appearance in the filled state. We also observed the presence of 2 D-island-like areas with no periodicity, which were surrounded by the 3 x 3 -Ag surface phase. These structures disappeared and the original root 3 x r oot 3 surface phase was recovered by annealing at 600 degrees C.