Vicinal Si(100) (4 degrees) shows perfectly ordered terraces with a wi
dth of 4 nm separated by double steps. Adsorption of Au at 800 degrees
C results in a dramatic change of the step morphology: the surface de
composes into areas which are perfectly Bat with a (100)orientation an
d [119]-facets, which compensate the macroscopic miscut. Macroscopic s
uper terraces with a width of 400 nm up to 4 mu m are formed, which ar
e extremely straight with a length limited only by the size of the sam
ple. (C) 1998 Elsevier Science B.V. All rights reserved.