Disruption of the Si(100)-2 x 1 surface by very low-energy ion irradiation

This study focuses on the basic surface processes occurring under surface irradiation with very low-energy ions. The experiment has been carried out by the use of an ultrahigh vacuum (UHV) low-energy ion beam system which can provide the mass-analyzed ion beam with the range 1-1000 eV and allows us to in situ analyze the surfaces by low-energy ion scattering (LEIS) and low-energy electron diffraction (LEED). It is shown that the atomic structure of Si(1 0 0)-2 x 1 surface is disrupted even under irradiation with the low-energy Ar ions of 1 eV. Moreover, from LEED study it is demonstrated that a weak Si(1 0 0)-1 x 1 surface has recovered from the disrupted surface by the mild annealing procedure at 570 K. The observed disruption phenomena by very low-energy ion irradiation are discussed based on the effects of momentum and ion dose. (C) 2000 Elsevier Science B.V. All rights reserved.