Low Power Phase Change Memory With Vertical Carbon Nanotube Electrode

Phase change memory (PCM) formed by Ge
₂
Sb
₂
Te
₅
(GST) on vertical carbon nanotube (CNT) filled contact plug is demonstrated in this paper. In order to achieve compatibility with the underlying process, the CNTs are synthesized using nickel catalyst at a low temperature. Reasonable contact characteristics between the CNTs and GST are achieved without material compatibility problem. Due to the small contact size of the CNT to the phase change material, a significant reduction in programming power is achieved compared to metal contact at the same via size. The temperature simulation result shows that the CNT filled via helps to reduce the programming area. The fabricated PCM on CNT filled via is able to endure more than 10
⁴
SET/RESET cycles without observable degradation.