High-spatial-resolution topographic imaging and dimer distance analysis of Si(100)-(2x1) using noncontact atomic force microscopy

The distance between bright spot in a dimer on the Si(100)-(2x1) surface imaged by noncontact atomic force microscopy (NC-AFM) is analyzed. We used in the analysis only high-spatial-resolution topographic NC-AFM images obtained using different tips at room temperature. Atoms in the dimer was clearly resolved, which enabled us to analyze the distance between two bright spots in the dinner statistically. The average distance was similar to that obtained in a previous study and the theoretical predition. The results indicated that dimer flipping was induced by the AFM tip during scanning and upper-upper atoms are imaged at room temperature.