Reliable ferroelectricity down to cryogenic temperature in wake-up free Hf0.5Zr0.5O2 thin films by thermal atomic layer deposition

Abstract The performance and reliability of ferroelectric thin films at temperatures around a few Kelvin are critical for their application in cryo-electronics. In this work, TiN/Hf 0.5 Zr 0.5 O 2 /TiN capacitors that are free from the wake-up effect are investigated systematically from room temperature (300 K) to cryogenic temperature (30 K). We observe a consistent decrease in permittivity ( ε r ) and a progressive increase in coercive electric field ( E c ) as temperatures decrease. Our investigation reveals exceptional stability in the double remnant polarization (2 P r ) of our ferroelectric thin films across a wide temperature range. Specifically, at 30 K, a 2 P r of 36 µ C/cm 2 under an applied electric field of 3.0 MV/cm is achieved. Moreover, we observed a reduced fatigue effect at 30 K in comparison to 300 K. The stable ferroelectric properties and endurance characteristics demonstrate the feasibility of utilizing HfO 2 based ferroelectric thin films for cryo-electronics applications.