Reconstructions and growth of Ag on Si(001)(2 × 1)

Abstract Complex growth and reconstructions of Ag on Si(001)(2 × 1) were studied by STM, LEED, AES and SEM. We find that Ag is first adsorbed at the silicon SB step edge and preferentially forms dimers on the Si terraces. At room temperature Ag grows in a pseudo Stranski-Krastanov (SK) mode. The first layer is not homogeneous and does not cover the substrate completely. In this layer several different structures coexist (e.g. (2 × 2), c(4 × 2), depending on the Ag induced buckling of the Si dimer rows). During the formation of the inhomogeneous layer, three-dimensional islands grow with the orientation Ag(111)//Si(001). At a substrate temperature of 770 K real SK growth is observed and the first layer is homogeneous. This layer has a (2 × 3) structure. On the top of this (2 × 3) layer, Ag islands grow with Ag(001)//Si(001).