Fabien Devynck

Band offsets at semiconductor-oxide interfaces from hybrid density-functional calculations.

Band offsets at semiconductor-oxide interfaces are determined through a scheme based on hybrid density functionals, which incorporate a fraction alpha of Hartree-Fock exchange. For each bulk component, the fraction alpha is tuned to reproduce the experimental band gap, and the conduction and valence band edges are then located with respect to a reference level. The lineup of the bulk reference levels is determined through an interface calculation, and shown to be almost independent of the fraction alpha. Application of this scheme to the Si-SiO2, SiC-SiO2, and Si-HfO2 interfaces yields excellent agreement with experiment.

Energy levels of candidate defects at SiC/SiO2 interfaces

Keywords: SiC/SiO2 interface ; band gap ; defects Reference CSEA-CONF-2009-004View record in Web of Science Record created on 2009-10-14, modified on 2017-05-12

Electronic properties of an epitaxial silicon oxynitride layer on a 6H-SiC(0001) surface: A first-principles investigation

Using a density functional scheme, the authors investigate the electronic properties of an epitaxial silicon oxynitride layer on a 6H-SiC(0001) surface, as recently realized experimentally. Simulated scanning-tunneling-microscopy images of filled and empty states agree well with the experiment, lending support to the proposed atomic structure. In accord with the experiment, the local density of states indicates that the electronic band gap in the thin silicate layer at the surface is close to that of bulk SiO2. The authors show that this effect results from the surface of the epitaxial adlayer acting as a high-barrier potential for the SiC states induced in the oxide band gap.

Atomistic model of the 4H(0001)SiC-SiO2 interface: structural and electronic properties

Through the sequential use of classical molecular dynamics and first‐principles relaxation methods, we generate an abrupt model interface for the 4H(0001)SiC‐SiO2 interface showing regular structural parameters without any coordination defect. The valence and conduction band offsets are calculated and found to be in fair agreement with the experimental values. Si‐2p core‐level shifts are calculated for this model interface and compared with available experimental data.