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

초록

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 (In2O3) and vanadium pentoxide (V2O5) ultrathin films were inserted as interlayers to reduce the leakage current of capacitors by using a titanium dioxide (TiO2) 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 TiO2 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 TiO2 dielectrics.

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