STUDY OF THE SI(111)7X7 SURFACE BY RHEED ROCKING CURVE ANALYSIS

Several integer and fractional rocking curves of reflection high energy electron diffraction (RHEED) from the Si(111)7 x 7 surface have been measured using a SIT camera. Dynamical calculation of RHEED intensity and minimization of the reliability factor have been employed to analyze the surface-normal atomic coordinates of the dimer-adatom-stacking fault (DAS) model. The most important parameters to be in agreement with the experimental results are outward displacements of the adatoms and the rest-atoms and inward displacements of the second and third layer atoms just below an adatom. It is also demonstrated that some rocking curves are sensitive for stacking faults.