Improved thermal stability, interface, and electrical properties of HfO₂ films prepared by pulsed laser deposition using in situ ionized nitrogen

Nitrogen is incorporated into thin HfO₂ films by pulsed laser deposition using in situ ionized nitrogen. The improved thermal stability and interfacial microstructure are further confirmed by high-resolution transmission electron microscopy. The composition of the thin film is investigated by x-ray photoelectron spectroscopy and electron energy-loss spectroscopy. Electrical studies show a property permittivity of 27.7 and low leakage current density were achieved by incorporation of a small amount (about 1 at. %) of nitrogen. The dominant conduction mechanisms of the Pt/HfO₂/p-Si structure are trap-assisted tunneling and Schottky emission at low electric field for the gate and substrate injection, respectively.