电荷俘获存储器数据保持特性第一性原理研究

发布时间：2018-08-14 11:38

【摘要】：本文研究HfO2掺入Al替位Hf杂质和氧空位共同掺杂对电荷俘获型存储器存储特性的影响.HfO2作为高介电常数材料由于具有缩小器件尺寸、提高器件性能等优势,被广泛用于CTM的俘获层.采用MS和VASP研究了HfO2俘获层中掺入Al对氧空位形成能的影响.同时计算了两种缺陷在不同距离下的相互作用能.计算结果表明在HfO2中掺入Al使得氧空位的形成能降低,并且三配位氧空位的形成能比四配位氧空位的形成能降低的更多.通过研究Al和三配位氧空位两种缺陷间不同距离的三种情况,计算结果表明当缺陷间距为2.107?时,体系的电荷俘获能最大;量子态数最多;布居数最小、Al—O键最长.通过研究三种体系写入空穴后键长的变化,得出当缺陷间距为2.107?时,写入空穴后体系的Al—O键长变化最小.以上研究结果表明,掺入Al后可以有效提高电荷俘获型存储器的数据保持能力.因而本文的研究为改善电荷俘获型存储器数据保持特性提供一定的理论指导.
[Abstract]:In this paper, the effect of HfO2 doped Al substituted HF impurity and oxygen vacancy on the storage characteristics of charge-trapping memory is studied. As a high dielectric constant material, HFO _ 2 has the advantages of reducing the device size and improving the device performance. It is widely used in capture layer of CTM. The effect of Al doping in HfO2 trapping layer on the formation energy of oxygen vacancy was studied by MS and VASP. At the same time, the interaction energy of two defects at different distances is calculated. The results show that the formation energy of oxygen vacancy is decreased by adding Al into HfO2, and the formation energy of tri-coordinated oxygen vacancy is much lower than that of four-coordinated oxygen vacancy. By studying three cases of different distances between Al and tri-coordinated oxygen vacancies, the calculated results show that when the defect spacing is 2.107? The maximum charge capture energy, the largest number of quantum states and the longest Al-O bond are obtained. By studying the change of bond length after the three systems were written into the hole, it was concluded that the defect spacing was 2.107? The Al-O bond length of the system is minimum when the hole is written. The results show that the data retention ability of charge capture memory can be improved by adding Al. Therefore, the research in this paper provides some theoretical guidance for improving the data retention characteristics of charge capture memory.
【作者单位】：安徽大学电子信息工程学院安徽省集成电路设计重点实验室;合肥师范学院电子信息工程学院;
【基金】：国家自然科学基金青年项目(批准号:21201052) 安徽省高校省级自然科学研究重点项目(批准号:KJ2014A208) 安徽高校自然科学研究重点项目(批准号:KJ2013A224) 安徽高校省级优秀青年重点项目(批准号:2013SQRL065ZD)资助的课题~~
【分类号】：TP333

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