Ferroelectricity in HfO2 thin films as a function of Zr doping

We have studied the effect of Zr doping, from 0% to 100%, on the ferroelectric properties of HfO
₂
. Amorphous Hf
_x
Zr
_1-x
O
₂
on TiN and Si substrates is deposited using atomic layer deposition (ALD) and then annealed in a rapid thermal processing (RTP) tool while capped by 20 nm of sputtered TiN. Based on our experiments, Zr doping of up to 50% results in ferroelectricity in polycrystalline Hf
_x
Zr
_1-x
O
₂
, whereas Zr doping of 70% and above shows antiferroelectricity. Our results show how the properties of ferroelectric HfO
₂
can be engineered through changing doping and annealing conditions, thereby demonstrating the flexibility of ferroelectric HfO
₂
for integration in future memory and logic devices.