[7a-C24-1~10] 6.6 Probe Microscopy

[7a-C24-7] The conductivity at the phase boundary of the Si(111)-7x7 surface

〇Masayuki Hamada¹, Hung-Hsiang Yang¹, Yukio Hasegawa¹ (1.ISSP, the Univ. of Tokyo)

Keywords:scanning tunneling potentiometry, surface conductivity, Si(111)-(7x7)

Scanning tunneling potentiometry (STP) enables us to map the topograph and electrostatic potential distributions simultaneously in atomic scale special resolution and microvolt level potential sensitivity on the surface under lateral current flowing parallel to the sample surface. We have developed UHV-STP, succeeded in STP on the Si(111)-(7x7) surface, and observed potential drops at the phase boundaries of the 7x7 reconstructed structure, which have not been reported before.
By carefully analyzing the obtained results, we found that the direction of local surface current is deviated from the macroscopic current direction by the presence of atomic steps on the surface.