Simulations of X-ray photoelectron diffraction for polytype analysis

Abstract

Single scattering cluster (SSC) simulations are used to explore the possibilities and the limitations of X-ray photoelectron diffraction (XPD) with standard laboratory X-ray sources in the field of polytype determination of silicon carbide (SiC) films. We show that the bulk emission dominates the diffraction patterns at energies of more than 1 keV. Effects due to surface reconstructions can be ignored in most cases. At least eight double layers contribute significantly to the diffracted intensity. The SSC simulations correctly reproduce the differences between the polytypes 3C, 4H and 6H SiC. Polytype determination is not obscured by different stacking terminations of the bulk crystal. Polytype specific peak splitting effects are explained by simulations for selected small clusters. XPD patterns of 2H SiC are predicted and discussed in comparison with 2H aluminium nitride.