Quasiparticle calculations of the electronic properties of ZrO$_2$ and HfO$_2$ polymorphs and their interface with Si

TL;DR

This study uses quasiparticle calculations to accurately determine the electronic band structures and band offsets of ZrO₂ and HfO₂ polymorphs and their interfaces with silicon, improving agreement with experimental data.

Contribution

The paper introduces quasiparticle corrections to density-functional-theory results, refining band offset predictions at oxide/Si interfaces for various polymorphs.

Findings

Valence band offsets are minimally affected by quasiparticle corrections.

Conduction band offsets increase by approximately 1.3 to 1.5 eV after correction.

Results align well with experimental measurements.

Abstract

Quasiparticle calculations are performed to investigate the electronic band structures of various polymorphs of Hf and Zr oxides. The corrections with respect to density-functional-theory results are found to depend only weakly on the crystal structure. Based on these bulk calculations as well as those for bulk Si, the effect of quasiparticle corrections is also investigated for the band offsets at the interface between these oxides and Si assuming that the lineup of the potential at the interface is reproduced correctly within density-functional theory. On the one hand, the valence band offsets are practically unchanged with a correction of a few tenths of eV. On the other hand, conduction band offsets are raised by 1.3--1.5 eV. When applied to existing calculations for the offsets at the density-functional-theory level, our quasiparticle corrections provide results in good agreement with the experiment.