Point defects in HfO2 high K gate oxide

This paper presents calculations of the energy levels of the oxygen vacancy and oxygen interstitial defects in HfO2 using methods not needing a band gap correction. The levels are aligned to those of the Si channel using the known band offsets. The oxygen vacancy gives energy levels in the upper gap of HfO2 and just above the Si gap. The vacancy is identified as the main electrically active trap in HfO2. The oxygen interstitial gives levels just above the oxide valence band.