IDENTIFICATION OF THE SI 2P SURFACE CORE-LEVEL SHIFTS ON THE SB SI(001)-(2X1) INTERFACE/

We investigated the effect of Sb-dimer-induced Si(001) relaxation on t he Si 2p core level by high-resolution photoemission spectroscopy. Two surface components, S and C*, were identified in the Si 2p core leve l measured on the Sb/Si(001)-(2 x 1) surface at 1 monolayer Sb coverag e. By using the Sb-Ge site exchange process, a Ge layer was inserted b etween the Sb dimers and the Si substrate to separate the Si 2p contri bution arising from different atomic layers. We demonstrated that S i ncludes the contribution of the first, second, and third layers, where as only the third layer contributes to C.