Excellent reliability of ferroelectric HfZrOx free from wake-up and fatigue effects by NH3 plasma treatment

With TiN/ferroelectric-HfZrO
x
(HZO)/TiN capacitors as the platform, NH
3
plasma treatment was employed at different HZO/TiN interfaces to investigate the impact on reliability. It has been electrically confirmed that HZO free from wake-up and fatigue effects up to 10
⁶
cycles (± 2.5 MV/cm, long pulses width of 1 ms) with high κ value of 29∼30, low leakage current and 2Pr of 20.2 μC/cm
²
can be achieved by treatments at both top and bottom interfaces. It is a great advance for HfO
2
-based FE and can be mainly attributed to significant reduction of oxygen vacancies (Vo) in HZO, especially treatment at bottom interface so that the interfacial TiO
x
Ny which causes oxygen-deficient HZO is effectively suppressed. NH
3
-treated HZO has been physically confirmed with fewer Vo (lower non-lattice oxygen by 7 %) that is beneficial to suppress pinned domain walls and generation of new Vo during cycling, eliminating wake-up and fatigue effects. Conspicuously mitigated fatigue is also maintained at 85 °C. The process ushers in a new approach to enhance the reliability for advanced FE-devices.