Scaling the Equivalent Oxide Thickness by Employing a TiO2 Thin Film on a ZrO2–Al2O3‐Based Dielectric for Further Scaling of Dynamic Random Access Memory

A metal–insulator–metal (MIM) capacitor consisting of TiN and ZrO2/Al2O3/TiO2 (ZAT) as electrodes and dielectric layer, respectively, is demonstrated for the development of next‐generation dynamic random access memory. The TiO2 layer deposited on ZrO2–Al2O3 exhibits a highly crystallized structure with an anatase phase and a dielectric constant of 40, resulting in a significant capacitance density enhancement compared with the conventional ZrO2/Al2O3/ZrO2 (ZAZ) film. The leakage current of the ZAT film can be controlled to a level comparable with that of the ZAZ film, and the carrier conduction mechanism is dominated by the thermionic emission mechanism. Consequently, a minimum equivalent oxide thickness scaling by ≈14% can be achieved by employing ZAT, compared with the conventional ZAZ.