Dynamics of Polarization Switching in Mixed Phase Ferroelectric-Antiferroelectric HZO Thin Films

The polarization switching dynamics for Hf
1-x
Zr
x
O
2
(HZO) integrated on InAs is studied as a function of pulse width and amplitude. Due to a mixed ferroelectric/antiferroelectric phase at x=0.8, a more gradual total polarization update is shown compared to a fully ferroelectric Hf
0.5
Zr
0.5
O
2
stack. A lowered operating voltage is achieved in Hf
0.2
Zr
0.8
O
2
by activating an inner ferroelectric hysteresis loop, and the switching dynamics of this inner hysteresis is studied. The Nucleation-Limited Switching (NLS) model is used to determine switching times for both stacks and show increased switching speeds for low-voltage polarization in the Hf
0.2
Zr
0.8
O
2
inner hysteresis, suggesting a benefit of using high-Zr HZO for higher speed and lower operating voltages.