Performance Optimization for Ferroelectric HfZrOx on a Ge Substrate by Modifying the Deposition Temperature

Hafnia ferroelectric-based Fe-FET devices have attracted increasing interest due to their CMOS compatibility, high scalability and low power consumption. Ge-based Fe-FETs could help overcome the shortcomings of Si-based Fe-FETs caused by the interface layer. In this work, the effect of the deposition temperature on the TiN/Hf
_0.5
Zr
_0.5
O
₂
/Ge device performance is systematically studied, which is helpful for finding the optimal conditions for Ge-based Fe-FETs. By adjusting the deposition temperature, the endurance property of the MFS capacitor is successfully enhanced to 2×10
⁵
cycles with a large minimum remnant polarization (2P
_r
≈ 46 μC/cm
²
). The observed phenomenon could be well understood by the effects of the deposition temperature and impurity concentration on the grain size.