Aluminum charge/dipole passivation induced by hydrogen diffusion in high-k metal gate

In this study, we have analyzed the influence of different high-k (HK), interfacial layer (IL) and metal gate on the Al effect. We show that hydrogen diffusion during the BEOL process can suppress totally the Al effect on work function. Solutions to stabilize the Al effect with respect to hydrogen diffusion are proposed and a model explaining the hydrogen and Al interaction is provided.