Convergent-beam RHEED in a dedicated UHV diffraction camera and applications to Si reconstructed surfaces

This paper describes the design and construction of a dedicated UHV diffrac tion camera with an energy filter for convergent beam reflection electron d iffraction (CB-RHEED). The advantages of this system for studying surface s tructures are demonstrated through applications to silicon (111) and (001) reconstructed surfaces. CB-RHEED patterns of the Si(001)-2 x 1 reconstructi on clearly show a mirror symmetry at room temperature, which is not present in dynamical calculations with the buckled dimer model. (C) 1999 Elsevier Science B.V. All rights reserved.