Journal of Vacuum Science & Technology A, Vol.16, No.6, 3471-3476, 1998
Angular-resolved valence-band spectroscopy of different reconstructed 3C-SiC (001) surfaces
We present angular-resolved valence-band spectroscopy data for the (3X2) and c(2X2) reconstructed (001) surface of cubic silicon carbide. The two reconstructions were prepared by annealing the sample in a flux of silicon atoms. In this way single domain reconstructed surfaces were achieved which was confirmed by low energy electron diffraction. The orientation of the surface unit cell with respect to the substrate orientation excludes the alternate dimer-row model for the (3X2) reconstruction of the surface. Angular-resolved valence-band spectra were recorded along the [1 (1) over bar 0] direction of the sample. Both surfaces reveal the photoemission characteristics known from angular integrating experiments. By comparison of the reconstructions, surface derived photoemission features were identified. In addition to the known V-1 and V-2 states of the (3 x2) reconstruction, we found a surface feature V-3 in a limited range of the surface Brillouin zone which is to our knowledge reported for the first time. The results are compared to ab initio calculations of the surface band structure. The data for the c(2X2) reconstructed surface are in accordance to calculations for the bridging dimer model. By comparing the data of the (3X2) structure to calculations of the (2 x I) surface band structure, we found indications for an assignment of the V1 and V2 states to dangling bonds and silicon dimers, respectively.
Keywords:ENERGY ELECTRON-DIFFRACTION;SOFT-X-RAY;INTERFACE FORMATION;SILICON-CARBIDE;BETA-SIC(001) SURFACES;RICH BETA-SIC(100);ATOMIC-STRUCTURE;PHOTOEMISSION;GROWTH;METALLIZATION