Ferroelectric Si-Doped HfO2 Device Properties on Highly Doped Germanium

Ferroelectric Si-doped HfO₂ thin films are integrated into three different device stacks with a p+ Ge substrate, a p+ Si substrate, and a TaN bottom metal gate. The ferroelectric behavior of the Si-doped HfO₂ thin films is strongly dependent on the bottom interfaces. The Si-doped HfO₂ thin films have favorably improved ferroelectric properties on the p+ Ge substrate due to the lack of a dielectric interfacial layer between HfO₂ and Ge. The low-voltage operation and cycling stability of Si-doped HfO₂ ferroelectric thin films on Ge can lead to the realization of high performance, robust Ge ferroelectric field-effect transistors for nonvolatile memory applications.