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.