First-principles study of NiSi_2/HfO_2 interfaces: Energetics and Schottky-barrier heights

摘要

The interface energetics and the Schottky-barrier heights (SBHs) of NiSi2/HfO2 gate stacks are investigated within the framework of first-principles calculations. It was found that the SBHs are interface structure dependent and vary with abrupt interfacial bonds. Based on the calculated interface formation energies of seven interface structures for two different chemical environments and the calculated SBHs, we propose adjusting hafnium or oxygen chemical potential together with silicon rich surface as an effective method to tune the barrier heights.