The impact of charge compensated and uncompensated strontium defects on the stabilization of the ferroelectric phase in HfO2
The impact of charge compensated and uncompensated strontium defects on the stabilization of the ferroelectric phase in HfO2
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DOI：
10.1063/1.4993110
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发表时间：
2017-08
影响因子：
4
通讯作者：
Robin Materlik;C. Kunneth;T. Mikolajick;A. Kersch
中科院分区：
文献类型：
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作者：
Robin Materlik;C. Kunneth;T. Mikolajick;A. Kersch
不同的掺杂剂具有特定的掺杂浓度，可以用来制备铁电HfO2薄膜。在这项工作中，它是在一个全面的第一性原理研究中探索的。密度泛函计算揭示了HfO2中与锶有关的缺陷的结构、形成能和总能量。我们发现电荷补偿缺陷和伴随的氧空位SrHfVO在能量上强烈地有利于非铁电的四方相P42/MNC。相反，没有氧空位的未补偿缺陷SrHf有利于铁电的、正交的Pca21相。根据形成能，在生产过程中，在富氧条件下容易形成未补偿缺陷。在整个寿命过程中存在的低氧分压会促进氧的损失，从而导致VO，因此，铁电的正交Pca21相的失稳伴随着漏电流的增加。这项研究试图从根本上解释...
Different dopants with their specific dopant concentration can be utilized to produce ferroelectric HfO2 thin films. In this work, it is explored for Sr in a comprehensive first-principles study. Density functional calculations reveal structure, formation energy, and total energy of the Sr related defects in HfO2. We found the charge compensated defect with an associated oxygen vacancy SrHfVO to strongly favour the non-ferroelectric, tetragonal P42/mnc phase energetically. In contrast, the uncompensated defect without oxygen vacancy SrHf favours the ferroelectric, orthorhombic Pca21 phase. According to the formation energy, the uncompensated defect can form easily under oxygen rich conditions in the production process. Low oxygen partial pressure existing over the lifetime promotes the loss of oxygen leading to VO, and thus, the destabilization of the ferroelectric, orthorhombic Pca21 phase is accompanied by an increase of the leakage current. This study attempts to fundamentally explain the stabilization...