New Phase-Change Materials by Atomic-Level Engineering the Dopants for Extremely Low Vth Drift at 85 °C and High Endurance 3D Crosspoint Memory : IBM/Macronix PCRAM Joint Project

New phase-change materials (PCM) from single composite target, which is made of GST-225 and dopants “A+O (oxygen)” using special setup magnetron sputtering are systematically studied their potential for 3D crosspoint memory technology. The PCM’s stable cycling endurance characteristic is the critical criterion to guarantee tight $\mathrm{V}_{\mathrm {th}}$ distribution during write cycles. We propose a new PCM material for 3D crosspoint memory technology. The new material, with optimized concentration, integrated with high Indium doped AsSeGe selector, demonstrates a wide $\mathrm{V}_{\mathrm {tS}}/ \mathrm{V}_{\mathrm {tR}}$ memory window (~1.5V memory window), stable 1E7 chips level write cycles (using 400ns SET box pulse time) and extremely low $\mathrm{V}_{\mathrm {tS}}$ and $\mathrm{V}_{\mathrm {tR}}$ drift characteristic (~0V) at 85 °C/1 day in 256kbits (64kbits are tested) ADM memory arrays.