XPS Study of Nitrided Hf-based high-k dielectrics

Nitridation of SiO$_2$ has been demonstrated to increase the dielectric constant of the resulting SiON dielectric allowing further scaling of conventional CMOS devices. Nitridation of Hf-based high-k dielectrics such as HfSiO and HfO$_2$ also results in increased dielectric constant. Besides increased k, nitrogen incorporation in Hf-based dielectrics increases films thermal stability. In this work we systematically study the incorporation of nitrogen in HfSiO and HfO$_2$ using plasma assisted nitridation and thermal treatments The nitrogen concentration and chemical interactions are studied using x-ray photoelectron spectroscopy and x-ray diffraction. The role of nitrogen on the electrical properties is also discussed.