Demonstration of Robust Breakdown Reliability and Enhanced Endurance in Gallium Doped HfO2 Ferroelectric Thin Films

In this letter, gallium doped HfO2(Ga:HfO
$_{{2}}{)}$
ferroelectric capacitors were fabricated and characterized. It is demonstrated that the W/Ga:HfO2/W capacitors under 650 °C rapid thermal annealing achieved a comprehensively good ferroelectricity, including a large remnant polarization (
$2{P}_{\text {r}}{)}$
of
$32.0~\mu \text{C}$
/cm2 and a small coercive electric field (
${E}_{\text {c}}{)}$
of 0.9 MV/cm. Moreover, the devices exhibit robust breakdown reliability including high breakdown electric field (
${E}_{\text {BD}}{)}$
(>4.5 MV/cm), and large breakdown voltage (>2.7 V) for 10-year time-dependent dielectric breakdown (TDDB) lifetime. Moreover, the robust endurance (
$10^{{10}}{)}$
was achieved in W/Ga:HfO2/W capacitors under 1 MHz loading. Such improvements were mainly attributed to the decreased
${E}_{\text {c}}/{E}_{\text {BD}}$
ratio from Ga effectively doping, which lowered the probability of breakdown during cycling. This work provides the perspective to optimize the reliability HfO2-based ferroelectric devices through doping engineering.