Polarization and interface charge coupling in ferroelectric/AlGaN/GaN heterostructure
Polarization and interface charge coupling in ferroelectric/AlGaN/GaN heterostructure
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铁电/AlGaN/GaN 异质结构中的极化和界面电荷耦合
DOI：
10.1063/1.3694283
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发表时间：
2012-03-12
影响因子：
4
通讯作者：
Zeng, Huizhong
中科院分区：
文献类型：
--
作者：
Zhang, Min;Kong, Yuechan;Zeng, Huizhong
在两种AlGaN/GaN金属-铁电-半导体(MFS)异质结中观察到了不对称的反向电容-电压(C-V)曲线移位行为。通过在自洽计算中引入铁电体的可切换的极性特性，揭示了铁电体和界面电荷之间的耦合效应。界面电荷所决定的铁电偶极子的初始取向相反是导致C-V特性不同的主要原因。得到的临界固定电荷密度为−1.27 × 1013 cm−2，这在C-V特性与铁电极化的关系中起着关键作用。研究结果为基于MFS结构的异极接口存储器件的设计奠定了基础。
Asymmetrical shift behaviors of capacitance-voltage (C-V) curve with opposite direction are observed in two AlGaN/GaN metal-ferroelectric-semiconductor (MFS) heterostructures with Pb(Zr,Ti)O3 and LiNbO3 gate dielectrics. By incorporating the switchable polar nature of the ferroelectric into a self-consistent calculation, the coupling effect between the ferroelectric and the interface charges is disclosed. The opposite initial orientation of ferroelectric dipoles determined by the interface charges is essentially responsible for the different C-V characteristics. A critical fixed charge density of −1.27 × 1013 cm−2 is obtained, which plays a key role in the dependence of the C-V characteristic on the ferroelectric polarization. The results pave the way for design of memory devices based on MFS structure with heteropolar interface.