电场下多元硫族化合物相变存储材料的结构演化与性能研究

项目名称： 电场下多元硫族化合物相变存储材料的结构演化与性能研究

项目编号： No.61274005

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 孙志梅

作者单位： 北京航空航天大学

项目金额： 108万元

中文摘要： 相变存储器（PCRAM）利用多元硫族化合物在低阻态和高阻态之间的快速可逆相变实现数据存储，具有非易失性、长寿命、抗辐照和优异的特征尺寸微缩性等优势，成为下一代半导体存储器的重要竞争者。跟当前的主流产品Flash竞争，PCRAM必须进一步降低工作电流、提高存储速度，设计新颖的器件结构和探索新材料是行之有效的解决途径。然而，相变材料在电脉冲下的结构演化和可逆相变机理不清楚，制约着新材料的有效设计；同时，薄膜的应力状态对电场下的结构演化有重要影响，但机理也不清楚。本项目针对上述基本科学问题，采用实验技术与理论计算相结合的方法，制备硫族化合物自由膜和受限薄膜，利用电脉冲处理及多种分析测试技术并结合理论计算，研究相变材料在电场下的结构演化与物理性能变化规律，探索薄膜应力状态和晶粒尺寸的影响，建立电场下可逆相变机理模型，为有效提高相变存储器的性能和探索新材料提供理论基础。

中文关键词： 硫族化合物相变存储材料；新型过渡金属氧化物；降低功耗和提高数据保持力；空位；掺杂

英文摘要： Phase-change random access memory (PCRAM), which utilizes the rapid reversible transition between the high and low resistance states of chalcogenide phase-change materials for data storage, is considered as the most promising next-generation universal memory type due to its merits of non-volatile, high density and high write-and-erase speed, low power consumption and good scalability. To compete with current Flash memory, it is necessary to further reduce the working current and improve the switching speed for PCRAM. For this purpose, it is an efficient way to design novel devices and to searching for new materials. However, the mechanism of phase change under current is not clear which limits the efficient pursuit of this type of work. On the other hand, the effects of stress state in films which play an import role during phase transition are not clear. In the present work, we will unravel the above basic problems on the basis of experiments and theoretical calculations. This project uses three experimental techniques to obtain stress-free and confined thin films, which are then treated by various current pulses. The structural evolutions are studied by both various types of experimental techniques and first principles calculations. Furthermore, the effects of film stress and grain size are also revealed. With

英文关键词： Chalcogenide phase change materials；novel transition metal oxides；power consumption and data retention；vacancy；dope