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基于密度泛理论的第一性原理以及VASP软件,研究了电荷俘获存储器(CTM)中俘获层HfO2在不同缺陷下(3价氧空位(VO3)、4价氧空位(VO4)、铪空位(VHf)以及间隙掺杂氧原子(IO))对写速度的影响.对比计算了HfO2在不同缺陷下对电荷的俘获能、能带偏移值以及电荷俘获密度.计算结果表明:VO3,VO4与VHf为单性俘获,IO则是双性俘获,HfO2在VHf时俘获能最大,最有利于俘获电荷;VHf时能带偏移最小,电荷隧穿进入俘获层最容易,即隧穿时间最短;同时对电荷俘获密度进行对比,表明VHf对电荷的俘获密度最大,即电荷被俘获的概率最大.通过对CTM的写操作分析以及计算结果可知,CTM俘获层m-HfO2在VHf时的写速度比其他缺陷时的写速度快.本文的研究将为提高CTM操作速度提供理论指导.
Based on the first principles of density functional theory and VASP software, the effects of HfO2 trapped in charge trapping memory (CTM) on different defects (VO3, VO4, hafnium vacancy (VHf ) And interstitial doping oxygen atoms (IO) on the write speed.The calculated values of charge trapping energy, band offset and charge trapping density of HfO2 under different defects were calculated.The results show that VO3, VO4 and VHf For single-trapping, IO is bisexual capture, HfO2 maximum capture at VHf, the most conducive to capture the charge; VHf when the band offset is minimal, charge tunneling into the capture layer is the easiest, that tunneling time is the shortest; at the same time Comparison of charge trapping density shows that VHf has the largest charge trapping density, that is, the probability of charge trapping is the largest.According to the write operation analysis and calculation results of CTM, it can be seen that the write speed of m-HfO2 in CTM capture layer is faster than that of other The writing speed of defect is fast.The research in this paper will provide theoretical guidance for improving the operation speed of CTM.