GOALI: To Understand Crystallization and Amorphization Dynamics in Phase-Change Memories by Linking Electro-Thermal Models, Electrical Experiments and TEM Characterization

非技术性描述：相变存储器是一种电子存储器概念，其利用的材料的电阻可以在高和低幅度之间快速和重复地切换，为更有效的计算和数据存储带来了巨大的希望。康涅狄格大学和IBM沃森研究中心之间的这个合作项目结合了计算，电气特性和显微镜，以更好地了解数据存储设备至关重要的几种相变材料现象。这项工作的结果可以为未来的材料合成和电子器件开辟新的可能性。该项目支持电气工程和材料科学与工程的不同学生群体的教育和培训，并通过几个外展计划向更广泛的社区提供支持。直接参与该项目的学生和博士后研究人员将受益于最先进的设施，并有机会为直接技术应用的基础研究做出第一手贡献。技术描述：相变存储器的大规模使用受到将纳米尺度元件加热到结晶或熔化以上所需的高功率的阻碍（对于熔融淬火非晶化）以及由于亚稳相的电阻漂移、元素偏析和在长时间循环时形成空隙而导致的有限可靠性。 如果这些器件特性能够得到改善，相变存储器就可以作为高容量、非易失性片上存储器集成在传统硅电子器件之上，从而显著提高性能和能源。该项目的重点是晶体-非晶转变，包括固态或电子非晶化的可能性，这可能导致更低的功率器件。此外，它还研究了电子特性（如电阻漂移）与微观结构变化之间的相关性。最后，该团队还解决了鲜为人知的六方过渡的细节，这种过渡通常不使用，但在某些情况下可能是有利的。这项工作需要开发原位透射电子显微镜实验技术，合适的电学表征技术和改进的模型，这些技术相结合，可以更好地了解不同时间和温度范围内的相变动力学。

Nontechnical description: Phase-change memory, an electronic memory concept that utilizes materials whose electrical resistance can be rapidly and repeatedly switched between high and low magnitudes, holds great promise for more efficient computation and data storage. This collaborative project between the University of Connecticut and IBM Watson Research Center combines computation, electrical characterization and microscopy to gain a better understanding of several phase-change materials phenomena that are critical for data storage devices. Results from this work can open new possibilities for future materials synthesis and electronic devices. This project supports the education and training of a diverse group of students in Electrical Engineering and Materials Science and Engineering, and also the broader community through several outreach programs. The students and post-doctoral researchers directly involved with the project benefit from access to state-of-the-art facilities and opportunities for first-hand contributions to fundamental studies with direct technological applications.Technical description: Large-scale use of phase-change memory has been hindered by the high power required to heat the nano-scale element above crystallization or melting (for melt-quench amorphization) and by limited reliability due to resistance drifts of the metastable phases, elemental segregation, and void formation upon extensive cycling. If these device characteristics can be improved, phase-change memory can be integrated on top of conventional silicon electronics as high capacity, non-volatile on-chip storage, leading to significant performance and energy improvements. This project focuses on the crystalline-amorphous transition, including the possibility of solid-state or electronic amorphization which can lead to lower power devices. In addition, it investigates correlations between electronic properties, such as resistance drifts, and changes in microstructure. Finally, the team is also addressing details of the lesser known cubic-hexagonal transition that is not typically used but may be advantageous in some cases. This work requires development of techniques for in-situ transmission electron microscopy experiments, suitable electrical characterization techniques and improved models that combined can provide a better understanding of phase transition dynamics across different time and temperature scales.