HfO 2中间隙氧缺陷特性第一性原理研究*

摘要

运用第一性原理计算研究了 HfO 2中间隙氧缺陷的特性。对 HfO 2中不同位置的间隙氧缺陷的形成能进行了计算，找出了最稳定的间隙氧缺陷位置，并对该位置缺陷计算了缺陷能级、态密度(DOS)和电荷俘获能；另外，还计算了间隙氧缺陷之间的距离对HfO 2性质的影响。计算结果显示间隙氧缺陷能够同时俘获电子和空穴，具有两性特征；俘获的电荷主要聚集在间隙氧和最近邻氧原子附近；间隙氧之间距离增大会使得缺陷之间由吸引变为排斥，排斥力随距离继续增大而减小，并且缺陷引入的受主能级量子态数显著增加，这有利于空穴隧穿电流增大，可以用来实现存储层电荷的快速擦除。%The characteristics of interstitial oxygen (IO )in HfO 2 have been studied by exceuting first priciple cac-ulation.The formation energies of IO s at different positions in HfO 2 have been calculated for the stablest site. The defect energy level,density of states (DOS)and charge trapping energy of this location have been compu-ted.The impact of distance between IO s on the features of HfO 2 has been calculated.The results of calculation confirm that IO has amphoteric property for it can capture electron and hole at the same time.The charges trapped mainly gather around the interstitial oxygen and the nearest neighbor atom of oxygen.The increasing distance between IO s changes the coulomb force between two defects from attraction to repulsion,and the repel-ling force decreases as the distance increases continually.Besides,the acceptor levels introducted by defect sig-nificantly increase the number of quantum states,which were advantageous to enhance the hole tunneling cur-rent that can be used to realize the rapid erasion of the storage layer charge.