Non-destructive analysis of ultrathin dielectric films

Using angle-resolved x-ray photoelectron spectroscopy (ARXPS) it is possible to determine thickness, composition and depth distribution information for ultrathin samples in the region of similar to5-10 nm. With ARXPS determining both quantitative elemental information and chemical state information, it provides chemical state profiles from surface and buried layers non-destructively. This paper illustrates how ARXPS data can provide measurements of overlayer thickness and interface layer thickness for high-k dielectric layers on silicon. Elemental and chemical state depth distribution information is also provided in the form of reconstructed concentration profiles. Further examples are provided where ARXPS has been used to study the influence of surface pretreatment of the silicon substrate prior to deposition of hafnium oxide. It will be shown that the pretreatment determines whether a silicon oxide or silicate is formed. Copyright (C) 2003 John Wiley Sons, Ltd.