Surface and interface of Ti(film)/SiC(substrate) system: a soft X-ray emission and photoemission electron microscopy study

Abstract

We have conducted a soft X-ray emission spectroscopy (SXES) and a photoemission electron microscopy (PEEM) study on the heat-treated Ti/4H–SiC system. This spectro-microscopy approach is an ideal surface and interface characterization techniques due to the non-destructive nature of SXES and the real-time surface imaging of PEEM. The Si L 2,3 and C K soft X-ray emission spectra, which reflect Si (s+d) states and C p states, respectively, revealed formations of Ti 5Si 3 and TiC in the reacted interfacial region of Ti (50 nm)/4H–SiC(0 0 0 1) sample. The surface of the Ti films on 4H–SiC samples during heat-treatment up to ∼850 °C was investigated by PEEM. The variation in brightness in the image of the sample was attributed to the surface deoxidation in the early stage of the treatment and to the formation of reacted region at the later stage. The darkening of the surface could be attributed to the formation of TiC and/or excess C atoms that could have migrated to the surface.