Surface Reactions of Co on SiO2 thin layer/Si substrate Studied by LEEM and PEEM

Abstract

To clarify how Co reacts with a SiO2 layer on Si substrates, the annealing processes were observed using low energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM). LEEM results using patterned substrate showed that Co silicide nano-dots form and that the Co diffusion length on the SiO2 layer is very small. From PEEM observations of a SiO2 layer with voids on Si substrate, we found that Co atoms in the void area, remain because of the formation of silicides, but those on the SiO2 surface disappear because metallic Co atoms easily diffuse. Co diffusion through the SiO2 layer to the Si substrate can compatibly explain these two results. © 2006 The Surface Science Society of Japan.