Effects of electronic confinement and substrate on the low-temperature growth of Pb islands on Si(100)-2 x 1 surfaces

Abstract

The growth of Pb films on the Si(1 0 0)-2 x 1 surface has been investigated at low temperature using scanning tunneling microscopy Although the orientation of the substrate is (1 0 0), flat-top Pb islands with (1 1 1) surface can be observed The island thickness is confined within four to nine atomic layers at low coverage Among these islands. those with a thickness of six layers are most abundant Quantum-well states in Pb(1 1 1) islands of different thickness are acquired by scanning tunneling spectioscopy. They are found to be identical to those taken oil the Pb(1 1 1) islands grown oil the Si(1 1 1)7 x 7 surface. Besides Pb(1 1 1) islands. two additional types of Pb islands are formed. rectangular flat-top Pb(1 0 0) islands and rectangular three-dimensional (3D) Pb islands, and both their orientations rotate by 90 degrees from a terrace to the adjacent one This phenomenon implies that the structures of Pb(1 0 0) and 3D islands are influenced by the Si(1 0 0)-2 x 1 substrate (C) 2009 Elsevier B.V. All rights reserved