SURFACE CORE-LEVEL SHIFTS OF SI(111)7X7 - A CRITICAL-EVALUATION OF THE SI 2P ANALYSIS

Three different teams have recently measured Si 2p high resolution syn chrotron radiation spectra from the 'prototypical' 7 x 7 reconstructio n of the clean Si(lll) surface. Although nearly identical line shapes were obtained, the model functions used in the analysis were rather di fferent, leading to somewhat dubious attributions of each surface shif ted component to a specific stuctural building block of the 7 x 7 reco nstruction. To objectively test these model functions we compare the c urve synthesis resulting from a new set of high resolution spectra acq uired independently. This comparison favors the model with five surfac e shifted components and consequently supports the corresponding assig nments. (C) 1998 Elsevier Science B.V.