Improvement Of Reliability And Speed Of Phase Change Memory Devices With N-7.9(Ge46.9bi7.2te45.9) Films

In this study, we propose a nitrogen-incorporated GeBiTe ternary phase of N-7.9(Ge46.9Bi7.2Te45.9) as a phase change material for reliable PCM (Phase Change Memory) with high speed operation. We found that the N-7.9(Ge46.9Bi7.2Te45.9) film shows the resistance value of 40 kO after annealing at 440 degrees C for 10 minutes, which is much higher than the value of 3.4 kO in the case of conventional N-7.0(Ge22.0Sb22.0Te56.0) films. A set operation time of 14 nsec was achieved in the devices due to the increased probability of the nucleation by the addition of the elemental Bi. The long data retention time of 10 years at 85 degrees C on the base of 1% failure was obtained as the result of higher activation energy of 2.52 eV for the crystallization compared to the case of N-7.0(Ge22.0Sb22.0Te56.0) film, in which the activation energy is 2.1 eV. In addition, a reset current reduction of 27% and longer cycles of endurance as much as 2 order of magnitude compared to the case of N-7.0(Ge22.0Sb22.0Te56.0) were observed at a set operation time of 14 nsec. Our results show that N-7.9(Ge46.9Bi7.2Te45.9) is highly promising for use as a phase change material in reliable PCMs with high performance and also in forthcoming storage class memory applications, too. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.