Solid-state graphitization of $\mathrm{Si}$-terminated $6\mathrm{H}\text{−}\mathrm{SiC}\left(0001\right)$ polar surfaces under thermal treatment in ultra-high-vacuum in the temperature region $500–1400°\mathrm{C}$ has been investigated by Auger electron spectroscopy (AES), photoemission (PE) and high-resolution electron energy loss spectroscopy (HREELS). Up to annealing temperatures of $900–950°\mathrm{C}$ core level $\mathrm{C}1s$ and $\mathrm{Si}2p$ photoemission spectra and corresponding phonon modes in HREEL spectra show the structure characteristics for $\mathrm{SiC}$. Further heating up to temperatures above $1050°\mathrm{C}$ causes intense graphitization of the surface layer with the formation of a well-ordered surface graphite phase at temperatures of about $1350–1400°\mathrm{C}$ with clearly distinguished characteristic graphite-derived phonon modes and a valence band electronic structure. Using angle-resolved HREELS and valence band photoemission the surface phonon mode and valence band dispersions of the formed graphite overlayer have been determined in the $\overline{\Gamma }\overline{M}$ direction over the whole energy range and the whole Brillouin zone. The graphitized layer shows four dispersive features (LA, LO, ZA, and ZO modes) and corresponding branches of valence band $\pi$ and $\sigma$ states which both agree with those characteristic of the natural monocrystalline graphite surface; an analysis of the measured dispersions allows us to conclude that at least 2 monolayers of well-ordered epitaxial graphite on top of the system have formed.

• Received 29 July 2003

DOI:https://doi.org/10.1103/PhysRevB.70.115421