STM Study of Au Adsorption on Si(111)-7 × 7 Surface: Voltage and Temperature Dependence

Abstract

We presented the scanning tunneling microscopy (STM) results on the study of Au adsorption at Si(111)-7 × 7 reconstructed surface. The voltage-dependent STM measurements indicated that there are at least three kinds of Au clusters and two types of single Au atoms adsorption on Si(111)-7 × 7 surface with Au coverage of about 0.2 monolayer. After the Au adsorbed Si surface was annealed at about 250 °C, the adsorbed Au clusters would diffuse into the Si substrate, and consequently create surface defects on the Si substrate. Sequentially annealed the sample at about 500 °C, the diffused Au would emerge out again and form larger 3-dimension Au clusters at the Si surface.