Investigation of Radiation Effect on Ge P-Channel Ferroelectric FET Memory

Zr-doped HfO2(HZO)-based germanium (Ge) p-channel ferroelectric FET (p-FeFET) memory devices with microwave annealing (MWA) followed by rapid thermal annealing (RTA) are employed as the platform to investigate the impact of $\gamma $ -ray radiation on the device performance. With a radiation dose of 1 Mrad, the memory window (MW) degrades from 2.5 V to 2.0 V accompanied by the significantly increased off-state current. The deleterious radiation effect is ascribed to the susceptible quality of the interface between the gate dielectric and source/drain region due to exacerbated charge trapping for the Ge substrate. These trapped charges also screen the polarization charges after applying a voltage pulse and lead to increased read-after-write latency. Nevertheless, compared with the irradiated HfO2-based FeFET memories in the literature, the Ge p-FeFETs in this work demonstrate competitive anti-radiation capability in terms of a large MW of 1.5 V even after $10^{{5}}$ cycles by bipolar stress (±4 V/ $1~\mu \text{s}$ ) and desirable retention up to 10 years under low voltage operation.