Silver-Induced 3×3 Phase on 6H-SiC(0001)$\sqrt{3}\times\sqrt{3}$ Surface

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