Oxygen passivation of vacancy defects in metal-nitride gated HfO ₂/SiO₂/Si devices

Abstract

We show that oxygen can be diffused through thin TiN layers to correct flatband voltage offsets in HfO2/SiO2 /Si structures, achieving nearly band-edge capacitance voltage characteristics without undue growth of parasitic SiO2. Photoemission reveals that the TiN remains conductive despite mild oxidation, although over-oxidation results in insulating layers. Secondary ionization mass spectroscopy of samples treated with isotopically labeled 18O was used to assess how much oxygen is required to fully passivate the defects caused by thermal processing of metallized HfO2/SiO2/Si devices. © 2009 American Institute of Physics.