Optimization of programming current on endurance of phase change memory

We study the effect of programming current on the endurance failure of phase change memory and propose a general scheme of optimizing programming currents for the most endurance cycles. We consider two major endurance failure modes, stuck-SET and open failure. We show that higher current does not necessarily cause, and even prevents the earlier open failure and attribute it to phase-dependent open-failure mechanisms. As for the stuck-SET failure, RESET current is optimized to balance material segregation effect and RESET current margin. The overall programming conditions are optimized by combining open and stuck-SET failure characteristic curves.