Electrostatic potential perturbation at the polycrystalline Si∕HfO2 interface

Comparison between potential barriers at the interfaces of polycrystalline Si with SiO2, SiO2∕HfO2, HfO2, and HfO2∕SiNx insulators indicates substantial perturbation of the image-force barrier shape at the Hf-containing interfaces. The internal photoemission of electrons suggests that Hf introduces charged centers with signs depending on the silicon doping type. In addition, at the interfaces of polycrystalline Si with HfO2 the barrier height is reduced by 0.2eV as compared to the (100)Si case by an interface dipole layer.