TiN/ferroelectric-HfZrOx (FE-HZO)/TiN capacitors were employed as the platform to investigate the impact of plasma treatment on reliability of FE-HZO. NH3 plasma treatment at different HZO/TiN interfaces was carried out to study the dependence of oxygen vacancies (Vo) on FE behaviors against cycling. It has been electrically confirmed that HZO free from wake-up and fatigue effects up to 106 cycles (±2.5 MV/cm, long pulses of 1 ms) with high $\kappa $ value of 29~30, low leakage current can be achieved by treatments at both top and bottom interfaces. It is a great advance for HfO2-based FE and is mainly attributed to significant reduction of Vo in HZO, especially the treatment at the bottom interface, which greatly suppresses the formation of oxygen-deficient HZO. Fewer Vo in NH3-plasma-treated HZO has also been confirmed by physical analysis. The plasma treatment has shed light on a feasible approach to enhance FE reliability.