Non-contact atomic force microscopic studies were made of Ge clusters on a Si(111)-(7 x 7) reconstructed surface. This technique permitted direct observation of the atomic structure of the Ge clusters on the Si(111). The clusters resided in the middle of a half unit cell on the (7 x 7) reconstruction surface, and were ~1.4Å higher than the Si adatoms. The Ge atoms resided in spaces between Si adatoms and on the Si/Ge atoms on the Si(111). The Si adatoms shifted from their original position through Ge adsorption, and interacted with the Ge atoms; accompanied by surface relaxation and a change in their spatial heights. In addition, the interatomic distance between the Ge atoms within the clusters was approximately 4.0Å. This was larger than that between the Ge atoms in the bulk (2.4Å).

Atomic Structure of Ge Clusters on Si(111)-(7 x 7) by Non-Contact AFM. I.Yi, Y.Sugimoto, R.Nishi, M.Abe, S.Morita: Nanotechnology, 2007, 18[8], 084013 (4pp)