Enhanced Endurance and Imprint Properties in Hf0.5Zr0.5O2-δ Ferroelectric Capacitors by Tailoring the Oxygen Vacancy

HfO2-based ferroelectric thin films are promisinginboth memory and logic devices owing to their compatibility with complementarymetal-oxide-semiconductor platforms and excellent thickness scalability.However, the fatigue and imprint effect are the main concerns, hinderingthe device's applications. In this work, we comprehensivelyinvestigate the impact of oxygen vacancies on the reliability of Hf0.5Zr0.5O2-& delta; (HZO)ferroelectric capacitors. The oxygen vacancy concentration was tailoredby varying the exposure time of the H2O precursor and oxygenplasma during atomic layer deposition. By decreasing the oxygen vacancyconcentration to 1.9%, the endurance is enhanced owing to the suppressionof defect migration under field cycling. In addition, a milder imprintwith coercive field shift of below 0.6 MV/cm under 120 & DEG;C isobtained, benefiting from the alleviation of the built-in field atthe ferroelectric/metal interfaces. The fabricated HZO capacitorswith considerable remnant polarization show superior reliability comparedwith the reported ones.