Impacts of Ta Buffer Layer and Cu-Ge-Te Composition on the Reliability of GeSe-Based CBRAM

We analyze the switching and retention properties of 65-nm integrated Cu(-Ge-Te)/(Ta)/GeSe conductive bridge random access memory devices operated at $50~\mu \text{A}$ . We evidence the crucial role played by a Ta buffer layer inserted between the Cu alloy and GeSe layers in decreasing the preforming current and in significantly improving the low-resistance state retention. Cu alloys of different compositions are tested to reveal lower device variability and longer retention with Cu2GeTe3 active electrode.