Study on electrical characteristics of amorphous InGaZnO MOS capacitors with High κ HfOxNy gate dielectric

High κ HfO_xN_y gate dielectric film is deposited on amorphous InGaZnO (a-IGZO) by radio frequency reactive sputtering HfO₂ target in N₂ ambient. The κ-value is approximately 1.5 times higher than pure HfO₂ owing to the existence of Hf-N bond. The results of SIMS, AFM and electrical properties measurement also indicate that nitrogen incorporation into HfO₂ ameliorate the surface morphology of dielectric film, suppress the atom diffusion at the interface, reduce the hysteresis, decrease the gate leakage current, thus enhance device performance.