Controllable Nanopit Formation on Si(001) with a Scanning Tunneling Microscope

The possibility of controlling the field-induced nanoscale-pit formation on the Si(001) surface by using an ultrahigh-vacuum scanning tunneling microscope has been demonstrated. Quadrilateral nanoscale-pits can be formed at high temperatures of 500-600°C by strong electric fields between the sample and the scanning tip through layer by layer removal of Si atoms from the silicon surface. The depth of nanopits increases linearly with the duration of applying electric fields. An array of uniformly shaped nanopits can be fabricated, indicating the controllability of this nanofabrication technique.