Layer-by-layer atomic manipulation on Si(111)-7x7 surface

Layer-by-layer removal of Si atoms from the Si(111)-7x7 surface was executed al room temperature by making a point contact of a biased W tip of scanning tunneling microscope (STM) to the sample surface. The adatom layer anti the three layers were controllably removed by tuning the sample bias voltage. In the created holes, clear atomic images were obtained. The current between the STM tip and substrate exhibited characteristic structures during the tip excursion, which are closely related with the atom removal process and the mature of the Si nanoscale wire, respectively. (C) 1996 American Institute of Physics.