Schroeder Uwe, Richter Claudia, Park Min Hyuk, Schenk Tony, Pešić Milan, Hoffmann Michael, Fengler Franz P G, Pohl Darius, Rellinghaus Bernd, Zhou Chuanzhen, Chung Ching-Chang, Jones Jacob L, Mikolajick Thomas
NaMLab gGmbH , Noethnitzer Straße 64 , 01187 Dresden , Germany.
IFW Dresden , Helmholtz Straße , Dresden , Germany.
Inorg Chem. 2018 Mar 5;57(5):2752-2765. doi: 10.1021/acs.inorgchem.7b03149. Epub 2018 Feb 15.
Recently simulation groups have reported the lanthanide series elements as the dopants that have the strongest effect on the stabilization of the ferroelectric non-centrosymmetric orthorhombic phase in hafnium oxide. This finding confirms experimental results for lanthanum and gadolinium showing the highest remanent polarization values of all hafnia-based ferroelectric films until now. However, no comprehensive overview that links structural properties to the electrical performance of the films in detail is available for lanthanide-doped hafnia. La:HfO appears to be a material with a broad window of process parameters, and accordingly, by optimization of the La content in the layer, it is possible to improve the performance of the material significantly. Variations of the La concentration leads to changes in the crystallographic structure in the bulk of the films and at the interfaces to the electrode materials, which impacts the spontaneous polarization, internal bias fields, and with this the field cycling behavior of the capacitor structure. Characterization results are compared to other dopants like Si, Al, and Gd to validate the advantages of the material in applications such as semiconductor memory devices.
最近，模拟研究小组报告称，镧系元素作为掺杂剂，对氧化铪中铁电非中心对称正交相的稳定性具有最强的影响。这一发现证实了镧和钆的实验结果，表明它们是迄今为止所有基于氧化铪的铁电薄膜中剩余极化值最高的。然而，对于镧系掺杂的氧化铪，目前还没有一个将薄膜的结构特性与电学性能详细联系起来的全面概述。镧掺杂氧化铪似乎是一种工艺参数窗口较宽的材料，因此，通过优化层中的镧含量，可以显著提高材料的性能。镧浓度的变化会导致薄膜本体以及与电极材料界面处的晶体结构发生变化，这会影响自发极化、内部偏置场，进而影响电容器结构的场循环行为。将表征结果与硅、铝和钆等其他掺杂剂进行比较，以验证该材料在半导体存储器件等应用中的优势。
