Sci Rep. 2012;2:360. doi: 10.1038/srep00360. Epub 2012 Apr 11.
The quest for universal memory is driving the rapid development of memories with superior all-round capabilities in non-volatility, high speed, high endurance and low power. Phase-change materials are highly promising in this respect. However, their contradictory speed and stability properties present a key challenge towards this ambition. We reveal that as the device size decreases, the phase-change mechanism changes from the material inherent crystallization mechanism (either nucleation- or growth-dominated), to the hetero-crystallization mechanism, which resulted in a significant increase in PCRAM speeds. Reducing the grain size can further increase the speed of phase-change. Such grain size effect on speed becomes increasingly significant at smaller device sizes. Together with the nano-thermal and electrical effects, fast phase-change, good stability and high endurance can be achieved. These findings lead to a feasible solution to achieve a universal memory.
对通用存储器的追求正在推动具有非易失性、高速、高耐久性和低功耗等卓越全面性能的存储器的快速发展。在这方面，相变材料具有很大的发展前景。然而，它们在速度和稳定性方面的矛盾特性，给实现这一目标带来了关键挑战。我们揭示了随着器件尺寸的减小，相变机制从材料固有的结晶机制（无论是成核主导还是生长主导）转变为异质结晶机制，这导致 PCRAM 速度显著提高。减小晶粒尺寸可以进一步提高相变速度。在较小的器件尺寸下，这种晶粒尺寸对速度的影响变得越来越显著。结合纳米热和电效应，可以实现快速相变、良好的稳定性和高耐久性。这些发现为实现通用存储器提供了可行的解决方案。
