Nitride passivation of the interface between high-k dielectrics and SiGe

In-situ direct ammonia (NH₃) plasma nitridation has been used to passivate the Al₂O₃/SiGe interfaces with Si nitride and oxynitride. X-ray photoelectron spectroscopy of the buried Al₂O₃/SiGe interface shows that NH₃ plasma pre-treatment should be performed at high temperatures (300 °C) to fully prevent Ge nitride and oxynitride formation at the interface and Ge out-diffusion into the oxide. C-V and I-V spectroscopy results show a lower density of interface traps and smaller gate leakage for samples with plasma nitridation at 300 °C