New Phase-Change Materials by Atomic-Level Engineering the Dopants for Extremely Low V_thDrift 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.