Nanostructure formation on Si (111) surface assisted by synchrotron radiation illumination - Characterization by scanning tunneling microscopy

The surface structures after the synchrotron radiation (SR) stimulated remo val of native oxide on Si (111) exactly oriented and 4 degrees misoriented surfaces were investigated by scanning tunneling microscopy. The exactly or iented surface showed large regions of atomically flat Si (III)-7X7 structu re, and was characterized by the formation of single bilayer steps nicely r egistered to the underlying crystal structure, clearly different from the d isordered step edge obtained by the usual high temperature thermal cleaning . The 4 degrees misoriented sample showed nearly uniformly spaced step bunc hes and terraces terminated by 7X7 unit cells in both SR assisted and therm al cleanings. (C) 2001 Elsevier Science BY. All rights reserved.