STRUCTURAL TRANSFORMATIONS OF THE SI(111)2 X 2-IN SURFACE-INDUCED BY STM TIP AND THERMAL ANNEALING

We have investigated In deposition on to Si(111)root 3x root 3-In surf ace by using low-energy electron diffraction (LEED) and scanning tunne lling microscopy (STM). A 2 x 2 structure was formed at 50-100 degrees C. Indium deposition at around 200 degrees C on the root 3x root 3 su rface or thermal annealing of the 2 x 2 surface resulted in the 4 x 1 structure formation but not through a root 31x root 31-phase, as takes place at higher temperatures. The difference between low and high tem perature surface phase formation is discussed. We have found that the 2 x 2 structure converts into the root 3x root 3 one during STM observ ation. This process was explained by STM-induced In atoms diffusion an d/or desorption. Possible atomic arrangement of the 2 x 2-In reconstru ction was proposed. (C) 1997 Elsevier Science B.V.