Interface Study of SiO 2 / HfO 2 /SiO 2 Stacks Used as InterPoly Dielectric for Future Generations of Embedded Flash Memories

We have investigated the integration of Hf-based material as Inter Poly Dielectric in flash memories devices. Electrical measurements showed the good properties of SiO 2 /HfO 2 /SiO 2 stacks. We then interested to the impact of the thermal budget on this specific stack which induces changes in the electrical properties. XPS measurements suggests those changes are due to the presence of an Hf-silicate layer at the SiO 2 /HfO 2 interface.