AN INQUIRY CONCERNING THE PRINCIPLES OF SI 2P CORE-LEVEL PHOTOEMISSION SHIFT ASSIGNMENTS AT THE SI SIO2 INTERFACE/

It has long been held that high resolution x-ray photoemission spectra of the Si 2p core level at SiSiO2 interfaces provide important struct ural information, and that any credible interfacial model must be able to account for these data. To this end it has traditionally been assu med that there existed a one-to-one relationship between chemically sh ifted spectral features and interfacial silicon atoms in specific form al oxidation states. A series of new measurements of Si 2p core level binding energies for cluster-derived Si/Si oxide interfaces appear to stand in direct contradiction to this critical assumption. In this art icle we present a critique of various responses to the challenge posed by the new observations. Particular attention is given to the logical consequences of either maintaining or rejecting the one-to-one relati onship between shifted features and formal silicon oxidation states an d to the challenges each of these responses must meet if they are to p revail. (C) 1996 American Vacuum Society.