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

最小的一点：相变存储器的极限本研究的目的是研究位尺寸小于10 nm的相变存储器器件的极限尺寸。相变材料（PCM）经历可逆相变，伴随着由电场和温度场引起的电阻率的急剧变化。 PCM是具有超低功耗的快速、高密度存储器的主要候选者。 这样的技术将使得能够实现远远超出现有技术的存储器设备的缩放，所述存储器设备由闪速存储器或其他电荷存储设备（如DRAM或SRAM）表示。 该ap-proach是研究纳米尺度的电场和温度场的基本原理，诱导相变，从而了解可以在PCM中形成的最小数据位。具体来说，拟议的工作将进行实验和模拟，确定最小的可寻址PCM位使用扫描探针技术和碳纳米管作为电极。 该研究的学术价值在于其彻底的方法，实现独立控制的纳米尺度的电场和温度分布的PCM。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来实现广泛的影响。这种新的理解可能会给消费电子设备带来根本性的变化。 这项研究将通过网络通信以及与高中教师、本科生、研究生和美国工业界的个人互动来实现更广泛的影响。

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.