Abstract
A modified X-ray photoelectron spectroscopy (XPS) analysis method is presented for accurately determining core level (CL) energy positions of gate dielectrics in MOS structures. In this method, XPS analysis is performed by measuring the CLs of various high-k oxides on SiO2 through a grounded ultra-thin Au film. The method enables the determination of CLs of oxides to be determined without worrying about any possible peak position shifts in XPS spectra caused by the electrical charging-up effect in oxides and/or dipoles formed at high-k/SiO2 interfaces. It is extended to the band-edge energy positions such as the valence-band maxima (VBMs) and the conduction-band minima (CBMs) of typical high-k oxides.