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

最小位：相变存储器的极限伊利诺伊大学厄巴纳-香槟分校威廉·p·金和埃里克·波普这项研究的目的是研究相变存储器器件的最终缩放，小于10纳米位尺寸。相变材料（PCM）在电场和温度场的作用下发生可逆的相变，并伴随着电阻率的剧烈变化。PCM是快速、高密度、超低功耗存储器的首选。这种技术将使存储设备的扩展远远超过目前的技术水平，以闪存或其他电荷存储设备（如DRAM或SRAM）为代表。该方法是研究纳米级电场和温度场诱导相变的基本原理，从而了解PCM中可以形成的最小数据位。具体来说，所提出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位。该研究的智力价值在于它彻底地实现了纳米尺度电场和温度分布在PCM中的独立控制。反过来，这些将允许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。该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，实现广泛的影响。这种新的认识可能会给消费电子设备带来根本性的变化。这项研究将通过网络交流，以及与高中教师、本科生、研究生研究人员和美国工业界的个人互动，产生更广泛的影响。

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.