Memory characteristics of filaments in tiny ReRAM structure

Clarification of memory characteristics of tiny cells is important for practical use of resistive random access memory (ReRAM). However, the limitation of semiconductor micro-fabrication technology hinders to obtain memory characteristics in tiny cell with an area comparable to the size of ReRAM filaments. In this paper, we established a method to prepare a very small memory cell by fabricating ReRAM structure on the tip of the cantilever of atomic force microscope (AFM). We also established a method to avoid the overshoot of set current. As a result, reset current was successfully reduced enough to suppress serious damage to the cantilever. The effective cell size was estimated to be less than φ 10 nm due to electric field concentration at the tip of the cantilever, which was confirmed by an electromagnetic field simulator based on finite element method.