Investigation of Hf₀.₅Zr₀.₅O₂ Ferroelectric Films at Low Thermal Budget (300 °C)

This study demonstrates annealing-free TiN/Hf0.5Zr0.5O2 (HZO)/TiN (MFM) ferroelectric (FE) capacitors using a low thermal budget process (300 ° C), without post deposition annealing (PDA) or post metal annealing (PMA). The remnant polarizations (
$2{P}_{\text {r}}$
) are 17.6 and
$21.8~\mu $
C/cm2 at the atomic layer deposition (ALD) temperatures (
${T}_{\text {dep}}$
) of 280 ° C and 300 ° C, respectively. The in-plane stress induced by the distorted TiN electrode could be the origin contributing to the emergence of low-thermal-budget ferroelectricity. In addition, as the
${T}_{\text {dep}}$
decreases, there is a reduction in crystallinity, orthorhombic phase (o-phase) composition,
${P}_{\text {r}}$
, dielectric permittivity (
$\kappa $
), and leakage current (J), leading to an enhancement in reliability. The demonstration of annealing-free ferroelectricity at temperatures as low as 300 ° C is helpful for the back-end-of-line (BEOL) process and the reliability of FE nonvolatile memory.