Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 USA.
Science. 2021 Sep 10;373(6560):1243-1247. doi: 10.1126/science.abj1261. Epub 2021 Sep 9.
Phase-change memory (PCM) is a promising candidate for data storage in flexible electronics, but its high switching current and power are often drawbacks. In this study, we demonstrate a switching current density of ~0.1 mega-ampere per square centimeter in flexible superlattice PCM, a value that is one to two orders of magnitude lower than in conventional PCM on flexible or silicon substrates. This reduced switching current density is enabled by heat confinement in the superlattice material, assisted by current confinement in a pore-type device and the thermally insulating flexible substrate. Our devices also show multilevel operation with low resistance drift. The low switching current and good resistance on/off ratio are retained before, during, and after repeated bending and cycling. These results pave the way to low-power memory for flexible electronics and also provide key insights for PCM optimization on conventional silicon substrates.
相变存储器 (PCM) 是柔性电子数据存储的一种很有前途的候选技术，但它的高开关电流和功耗通常是缺点。在这项研究中，我们在柔性超晶格 PCM 中展示了约 0.1 兆安培/平方厘米的开关电流密度，这比在柔性或硅衬底上的传统 PCM 低一到两个数量级。这种较低的开关电流密度是通过超晶格材料中的热限制以及孔型器件中的电流限制和热绝缘柔性衬底实现的。我们的器件还具有低电阻漂移的多级操作。在反复弯曲和循环之前、期间和之后，低开关电流和良好的电阻开关比得以保留。这些结果为柔性电子产品的低功耗存储器铺平了道路，也为传统硅衬底上的 PCM 优化提供了关键见解。
