Recrystallization process controlled by staircase pulse in phase change memory

•We proposed a novel staircase pulse programming method to control recrystallization region.•We predicted the recrystallization region change with increasing amplitude of the second subpulse by finite element analysis.•The well-controlled gradual resistance was obtained.•This technique is very useful for freely-achievable multilevel storage.

In this study, we investigate the recrystallization process in phase-change memory by applying staircase pulses. The controlled recrystallization process is expected to be applied to freely achievable multilevel storage. Simulation results exhibit that the phase change material is heated above its melting point during the first subpulse of the staircase pulse and then annealing temperature can be controlled by varying amplitude of the second subpulse. This implies that the recrystallization region is controllable by applying staircase pulses. V-shaped resistance change vs. the amplitude of the second subpulse, which is caused by the growth and the shrinkage of recrystallized region, is obtained at each width of second subpulse.

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