Suppression of Filament Overgrowth in Conductive Bridge Random Access Memory by Ta(2)O(5)/TaO(x) Bi-Layer Structure

Bi-layer structure has been widely adopted to improve the reliability of the conductive bridge random access memory (CBRAM). In this work, we proposed a convenient and economical solution to achieve a Ta(2)O(5)/TaO(x) bi-layer structure by using a low-temperature annealing process. The addition of a TaO(x) layer acted as an external resistance suppressing the overflow current during set programming, thus achieving the self-compliance switching. As a result, the distributions of high-resistance states and low-resistance states are improved due to the suppression of the overset phenomenon. In addition, the LRS retention of the CBRAM is obviously enhanced due to the recovery of defects in the switching film. This work provides a simple and economical method to improve the reliability of CBRAM.