Metallic oxygen barrier diffusion applied to high-κ deposition

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A thin metallic interlayer was deposited on Si and Si/SiO2 substrate prior to the sputtering of HfO2 films. The metallic interlayer, in fact, acts as an oxygen barrier during the HfO2 deposition, preventing the formation of a low-κ layer at the high-κ/Si interface. After annealing, the metal diffuses in the HfO2 film. When the thickness of the metallic interlayer is properly adjusted, with respect to the thickness of the HfO2 film, the interfacial layer at HfO2/Si interface can almost be suppressed, thus improving the electrical properties of the gate stack.