Effective work function tunability and interfacial reactions with underlying HfO2 layer of plasma-enhanced atomic layer deposited TaCxNy films.

This study examined the interfacial reaction of plasma-enhanced atomic layer deposited TaCxNy films with underlying SiO2 and HfO2 layers, as well as their effective work functions (EWFs). The adoption of Ar/H2 plasma as a reducing agent suppressed the interfacial reactions resulting in a lower electrical thickness. However, it increased the interface state density due to the massive Ar+ plasma damage on the dielectric films. The interfacial reactions were suppressed in TaCxNy on HfO2 compared with that on SiO2. The EWF of TaCxNy with the H2 plasma and Ar/H2 plasma on HfO2 was ∼4.9–5.2 and ∼4.6 eV, respectively. [ABSTRACT FROM AUTHOR]