Tip-Sample Interactions in the Scanning Tunneling Microscope for Atomic-Scale Structure Fabrication

• Published in: Japanese Journal of Applied Physics 1993-03, Vol.32 (3S), p.1470
• Main Authors: Aono, Masakazu, Kobayashi, Ataru, Grey, Fran\ccois, Uchida, Hironaga, Huang, De-Huan
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.32.1470

In a scanning tunneling microscope (STM) operated in ultra-high vacuum, if we place a well-prepared W tip above the Si(111)-7×7 surface at a separation of ∼1 nm and apply an appropriate voltage pulse to it, we can extract a single Si atom from a predetermined position routinely at room temperature. The extracted Si atoms are redeposited onto the surface with a certain probability, their positions always being at a fixed crystallographic site. The redeposited Si atoms can be displaced intentionally to other crystallographically equivalent sites. In case of the Si(001)-2×1 surface, usually two Si atoms forming a dimer are extracted together. For both surfaces, Si atoms at crystallographically different sites including step edges are extracted with different probabilities. The microscopic mechanisms of these processes are discussed.