哈夫尼亚
铁电性
材料科学
双层
电容器
X射线光电子能谱
氧化物
光电子学
兴奋剂
纳米技术
化学工程
复合材料
化学
电介质
陶瓷
电压
电气工程
立方氧化锆
膜
冶金
工程类
生物化学
作者
Hunbeom Shin,Venkateswarlu Gaddam,Sung-Jong Jeon,Yeongseok Jeong,Giuk Kim,Yixin Qin,Sanghun Jeon
摘要
Recently, hafnia-based ferroelectrics are currently being investigated as next-generation memory devices due to their excellent CMOS process compatibility and functionality. However, some of the ferroelectric devices commonly exhibit an imprint effect due to charged defects around the interfacial layer, which has negative impacts on the ferroelectric memory devices. However, it can be applied to various applications as long as the imprint field is carefully adjusted. In this work, we introduced a strategy to control the imprint field in bilayer capacitors by utilizing tantalum oxide (TaO) interfacial layers and various Zr contents in Hf0.83Zr0.17O2 (HZO) films. The TaO layer (1 nm) was inserted into the bilayer capacitors to alter the imprint field's (positive or negative) direction. Whereas to control the imprint fields, we adjusted the Zr doping content (17%–83%) in the ferroelectric HZO films (8 nm). As the Zr content increased, reduced imprint fields were observed in those bilayer capacitors. In addition, it was found that a high imprint field (+2.43 MV/cm) was observed in Hf-rich films (Hf0.83Zr0.17O2) due to the higher amount of oxygen vacancies. In addition, we examined those oxygen vacancies through x-ray photoelectron spectroscopy depth profile analysis by considering sub-oxide fractions in the tantalum, which further confirms the root cause of the imprint field variations in the bilayer capacitors. Our study will contribute to a deeper understanding of imprinted hafnia-based ferroelectrics and will provide an insight into devices that utilize the imprint effect.
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