Effects of Carbon Lateral Implantation in Ge-rich GeSbTe Phase-Change Memory

In this work we investigate the effects of lateral Carbon ions implantation in 4 kb Ge-rich GeSbTe (GST) Wall-type Phase-Change Memory (PCM) arrays with the objective of improving their reliability. Differently from previous studies, the ion beam was here tilted and tuned to localize Carbon at the lateral interface between the phase-change material and the SiN encapsulation layer after the patterning steps, known to have an important impact on the cell performances. Through the characterization of 4 kb arrays combined with TEM/EDX analyses, we study the effects of such localized Carbon on the device performances. Carbon laterally implanted devices show a more reliable forming process, a variability reduction of the SET and RESET states and an enhanced data retention at 250°C.