Effects of graphene intercalation on dielectric reliability of HfO2 and modulation of effective work function for Ni/Gr/c-HfO2 interfaces: First-principles study

Abstract

We have investigated the effects of graphene intercalation on dielectric reliability of HfO2 for Ni/Gr/HfO2 interfaces, and the effects of graphene intercalation and interfacial atom vacancy on the effective work function (EWF) of Ni/Gr/HfO2 interfaces using first-principle calculation based on density functional theory. The calculated results indicate that graphene intercalation can improve dielectric reliability of HfO2 dielectric even for the interfaces having interfacial oxygen vacancy or a small amount carbon vacancy. Moreover, the calculated results indicate that, inserting graphene into Ni/HfO2 interface induces the EWF's to decline, and controlling interfacial oxygen or carbon vacancy can effectively tune the EWF of Ni/Gr/HfO2 interface. Our work strongly suggests that the use of graphene synthesized into Ni/HfO2 interface is a very effective way to improve the interface quality, and controlling interfacial oxygen or carbon vacancy is also an attractive and promising way for modulating the EWF of Ni/Gr/HfO2 interfaces.