Effect of the Bottom Electrode Contact (BEC) on the phase transformation of N2 doped Ge2Sb2Te 5 (N-GST) in a Phase-change Random Access Memory

With respect to the operation of a Phase-change Random Access Memory (PRAM or PcRAM), we studied the effect of the contact between the electrode metal and the chalcogenide glass, N2 doped Ge2Sb2Te5 in this report. We investigated a change of the resistance-programming current pulse (R-I) curve varying the contact size and the electrode material. Also we tested the surface oxidation of the electrode. We found that the programming current, the resistance of the programmed state (“RESET”) and the erased state (“SET”) were highly dependent on the above parameters. These results are presented and a more effective way to the high density PRAM will be proposed.