Deterministic Formation of Conductive Filaments in Resistive Memories With Cavities Formed by Nanosphere Templates

This letter introduces a new method for creating resistive random-access memory (RRAM) with predictable switching characteristics. The method uses cavities, formed by nanosphere templates, to guide the creation of conductive filaments in the device. This approach not only reduces switching energy and enhances repeatability, but also eliminates the need for an additional photolithography step to create these nanometer-scale cavities in a uniform honeycomb-like layout. The diameter of the cavity can be easily controlled by etching the nanospheres. While control RRAM devices showed a higher and broader SET voltage distribution of $3.5\pm 0.34$ volts, the cavity-enhanced structure consistently demonstrated repeatable switching with lower and narrower SET voltage distributions. These distributions were in the range of $2.08\pm 0.13$ V, $1.7\pm 0.12$ V, and $1\pm 0.1$ V for devices sized 500, 300, and 100 nm respectively. It was observed that lower and narrower parameter distributions directly correlated with the cavity diameters.