Atomic and electronic structures of heat treated 6H–SiC surface

We have studied heat-treated 950–13008C.6H–SiC 0001.Si and 0001.C face with photoemission spectroscopy using synchrotron radiation SR-PES.and low energy electron diffraction LEED.. We observed LEED patterns of SiC 1=1, ʹ3 =ʹ3 ,ʹ3 =ʹ3 q6ʹ3 =6ʹ3 and graphite 1=1 sequentially with increasing heating temperature for 0001.Si face and SiC 1=1 for 0001.C face, respectively. We have measured Si 2p.spectra and valence band energy distribution curves VB-EDCs.. The trend of sublimation of Si atoms from surface is different between Si- and C-face.ʹ3 =ʹ3 superstructure must be Si-derived. The 6ʹ3 =6ʹ3 structure could be explained as a moire´ pattern caused by monolayer-graphite sitting on SiC surface. Si 3s-derived state of SiC 1=1 is different between SiC 1=1 for Si- and C-face. It is suggested that a single crystal graphite layer grows on Si-face and a polycrystalline graphite is formed on C-face for heated specimens above 11508C. q1998 Elsevier Science B.V. All rights reserved