Point defects in ZrO2 high-κ gate oxide

This paper presents calculations of the electrical energy levels of the main point defects in ZrO₂, the oxygen vacancy and the oxygen interstitial. The levels are aligned to those of the Si channel using the known band offsets. The oxygen vacancy gives an energy level in the Si gap or just above the gap, depending on its charge state. This is the main electrically active defect and trap in ZrO₂ films. The oxygen interstitial gives levels just above the oxide valence band, and the neutral interstitial also gives a level near the Si conduction band.