Intrinsic fixed charge and trapping properties of HfAlO interpoly dielectric layers

International audienceThe objective of this work is to investigate the fixed charge and the trapping properties of SiO 2 – HfAlO – SiO 2 (OHO) tri-layer stacks as interpoly dielectrics of NVMs. This study focuses on the key role played by the HfAlO composition. We show that the intrinsic fixed charge content increases with the Al concentration, while the trapping capabilities, during a gate stress, increases with the Hf ratio of the compound. We argue also that the charge trapping happening during a gate stress is mainly located at the high-k interface rather than in the volume. Retention characteristics are also shown. Finally, the experimental data are explained through a model based on a SRH approach