Electronic and atomic structures of metal(Ni, Co, Au) /Si(111) contacts: soft X-ray spectroscopy and photoelectron spectroscopy

Abstract

A nondestructive surface and interface structure analysis was successfully carried out using the soft X-ray emission spectroscopy (SXES) method for transition metal (Ni, Co) silicides and metal(very-thin-layer)/Si(substrate) contact systems. The method is based on the following facts: (1) the Si L 2.3 valence band SXES spectrum of a Si-compound (or alloy) shows a clear difference from that of Si crystal. (2) The soft X-ray production depth increases with increasing incident electron energy. The valence band electronic structure was also discussed in comparison with the X-ray photoelectron spectroscopy study.