A core level and valence band photoemission study of the (111) and ((1)over-bar (1)over-bar (1)over-bar) surfaces of 3C-SiC

A core level and valence band photoemission study of thick 3C-SiC(1 1 1) an d 3C-SiC((1) over bar (1) over bar (1) over bar) epilayers grown by sublima tion epitaxy is reported. The as introduced samples show threefold 1 x 1 lo w-energy electron diffraction patterns. For the Si face root3 and 6 root3 r econstructed surfaces develop after in situ heating to 1100 degreesC and 13 00 degreesC, respectively. For the C face a 3 x 3 reconstruction form after heating to 980 degreesC. A semiconducting behavior is observed for the roo t3 and 3 x 3 reconstructed surfaces while the 6 root3 reconstruction show a Fermi edge and thus a metallic-like behavior. The surface state on the roo t3 surface is investigated and found to have Lambda (1) symmetry and a tota l band width of 0.10 eV within the first surface Brillouin zone. For the Si 2p and C Is core levels binding energies and surface shifted components ar e extracted and compared to earlier reported results for 6H- and 4H-SiC. (C ) 2001 Elsevier Science B.V. All rights reserved.