GaSb基类超晶格相变薄膜的制备及其在相变存储器中的应用

项目名称： GaSb基类超晶格相变薄膜的制备及其在相变存储器中的应用

项目编号： No.61306147

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 吕业刚

作者单位： 宁波大学

项目金额： 25万元

中文摘要： 相变存储器(PCRAM)是国际上公认的最具潜力的下一代非易失性存储器之一。PCRAM的研发重点集中在如何降低操作电流和功耗，提升相变速度和数据保持力。相变层是PCRAM的核心，其性能优化对PCRAM器件性能至关重要。在本项目中，将类超晶格结构引入相变层，相变层采用热稳定性高的相变材料(GaSb)和主流Te基硫系化合物(Sb-Te、Ge-Te等)以纳米级厚度交替生长而成。利用类超晶格结构的散射效应降低相变层的热导率，以达到降低操作电流和功耗的目的。此外，该相变层可以利用GaSb热稳定性好和结晶速度快的特性使PCRAM的数据保持力和操作速度得以提升。研究内容包括：掌握纳米尺度相变材料可控生长的制备技术，优化相变存储器单元的制备工艺；建立相变层的周期厚度和界面数与材料及器件性能的关系；探讨界面处原子迁移对器件性能的影响；掌握类超晶格相变层的相变机理和热传导机制，最终实现器件性能的提升与调控。

中文关键词： 相变存储器；多级存储；多层薄膜；类超晶格；

英文摘要： Phase change random access memory (PCRAM) is internationally considered to be one of the most promising candidates for next-generation nonvolatile memories. PCRAM researches concentrate on how to reduce operating current and power, and to improve the speed and data retention. Phase change layer is the core of the PCRAM. The performance optimization of phase change material is essential for the device properties of PCRAM. In this project, The superlattice-like structure is embedded in the phase change layer which is alternately formed by the high thermal stability of GaSb and the mainstream Te-based Chalcogenides (Sb-Te, Ge-Te) with nanometer thickness. The reduction in operating current and power can be achieved due to the low thermal conductivity as a result of scattering effect of superlattice-like structure. In addition, the high thermal stability and crystallization speed of GaSb can improve the data retention and speed of PCRAM. The main research contents include controlled deposition technology of nanometer-scale phase-change materials and the optimization of fabrication process of PCRAM cell. Effects of periodic thickness and interface number of phase change layer on material and device properties are investigated. The relationship between atomic migration and device property is analyzed. The phase-change

英文关键词： phase change memory；multilevel storage；multilevel film；superlattice-like；