Scaling ferroelectric HZO thickness for low power Ge MFS-FTJ memories

Ge MFS capacitors with ultrathin ferroelectric HZO are prepared to fabricate FTJ devices. 5 nm HZO after wake-up show good reliability and excellent polarization switching characteristics featuring high remanent polarization
$\mathrm{P}_{\mathrm{r}}\sim 22.2\ \mu \mathrm{F}/\text{cm}^{2}$
and low coercive voltage V
c
∼ 1.1V. These performance characteristics create the prospect for low voltage (< 2 V) /low power NVM FTJ memories. According to our modeling, 5 nm FTJs suffer from low Jon, but thinner HZO devices combine high J
on
(>0.1 A/cm
²
) and relatively large TER (>70). A sufficiently large J
on
has been measured on our 3-nm HZO FTJs, albeit with lower-than-expected TER and Ion/Ioff ratios.