Leakage Current Minimization of TiO2-Based Metal–Insulator–Metal Capacitors Using High-Work-Function In2O3 and V2O5 Ultrathin Interlayers

High capacitance and low leakage current of capacitors are crucial for scaling down dynamic random access memory (DRAM). In this study, high-work-function (WF) indium sesquioxide (In
₂
O
₃
) and vanadium pentoxide (V
₂
O
₅
) ultrathin films were inserted as interlayers to reduce the leakage current of capacitors by using a titanium dioxide (TiO
₂
) dielectric, which has a particularly high dielectric constant. This modification improved the morphology and increased the conduction-band offset. Consequently, the leakage current was reduced by more than 3500 times compared with that of the device without an interlayer. Furthermore, each interlayer functioned as a seed layer in the growth of TiO
₂
and exhibited a change in the crystallinity of the anatase phase, which resulted in an increase of 12.5% in capacitance. These results revealed that the proposed method effectively reduced the leakage current and maintained capacitor capacitance, thereby addressing a critical problem of TiO
₂
dielectrics.