The Smallest Bit: Ultimate Limits of Phase Change in Nanometer-Scale Memory Devices

最小的位：相变存储器的最终极限威廉·P·金和伊利诺伊大学厄巴纳-香槟分校的埃里克·波普这项研究的目的是调查相变存储器件的最终扩展，小于10纳米位大小。相变材料在电场和温度的共同作用下会发生可逆相变，同时伴随着电阻率的剧烈变化。PCM是具有超低功耗的快速、高密度存储器的主要候选者。这样的技术将使存储设备能够扩展到远远超出现有技术的水平，所述存储设备以闪存或其他电荷存储设备如DRAM或SRAM为代表。其方法是研究引起相变的纳米级电场和温度场的基本原理，从而理解在PCM中可以形成的最小数据位。具体地说，这项拟议的工作将进行实验和模拟，以确定使用扫描探针技术和碳纳米管作为电极的最小可寻址PCM比特。这项研究的智能价值在于它彻底实现了对相变材料中纳米级电场和温度分布的独立控制。反过来，这些将使人们在理解相变存储器中使用的材料的行为方面取得重大进展。这项研究将通过提供有关未来数据存储系统的最终速度、大小和寿命限制的信息来产生广泛的影响。这种新的理解可能会给消费电子设备带来根本性的变化。这项研究将通过与高中教师、本科生、研究生和美国工业界的网络沟通和个人互动，实现更广泛的影响。

The Smallest Bit: Ultimate Limits of Phase Change MemoryWilliam P. King and Eric PopUniversity of Illinois Urbana-ChampaignThe objective of this research is to investigate the ultimate scaling of phase change memory de-vices, below 10 nm bit size. Phase-change materials (PCM) undergo a reversible phase change accompanied by a drastic change in resistivity, induced by electric and temperature fields. PCM are prime candidates for fast, high-density memory with ultra-low power consumption. Such a technology would enable scaling of memory devices much beyond the present state of the art, represented by Flash memory or other charge storage devices like DRAM or SRAM. The ap-proach is to investigate the fundamentals of nanometer-scale electric and temperature fields that induce phase change, resulting in an understanding of the smallest data bits that can be formed in PCM. Specifically, the proposed work will perform experiments and simulations that determine the smallest addressable PCM bit using scanning probe techniques and carbon nanotubes as the electrodes. The intellectual merit of the proposed research lies in its thorough approach for achieving inde-pendent control of nanometer-scale electric fields and temperature distributions in PCM. In turn, these will allow a significant advance in understanding the behavior of materials used in phase change memory. The research will achieve broad impact by providing information about the ultimate speed, size, and longevity limits of future data storage systems. This new understanding could bring about radical changes in consumer electronics devices. The research will achieve additional broad im-pact through web-enabled communication, and personal interactions with high school teachers, undergraduate students, graduate researchers, and U.S. industry.