HfO_(2)基铁电材料准静态负电容机理  

On the Quasi-static Negative Capacitance in HfO_(2)-based Ferroelectrics

作　　者：尹志岗[1,2] 董昊 程勇 吴金良 张志伟[1] 张兴旺 YIN Zhigang;DONG Hao;CHENG Yong;WU Jinliang;ZHANG Zhiwei;ZHANG Xingwang(Key Lab of Semiconductor Materials Science,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院半导体研究所半导体材料科学重点实验室,北京100083 [2]中国科学院大学材料与光电研究中心,北京100049

出　　处：《北京工业大学学报》2025年第3期269-276,共8页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(62074145,62274162)。

摘　　要：HfO_(2)基铁电薄膜的负电容现象提供了解决微纳电子器件功耗问题的可行策略,但其物理图像却一直饱受争议。基于Landau-Devonshire和Landau-Khalatnikov方程,对铁电HfO_(2)/介质双层体系开展了理论模拟。结果表明:根植于零场吉布斯自由能及准静态极化-电场曲线的准静态负电容理论,难以如实反映极化-电场动态演化轨迹。与准静态负电容理论的预言不同,HfO_(2)/介质体系的负电容强烈依赖于介质层分压效应,具有瞬态属性。回滞现象与Landau-Khalatnikov方程中的阻尼系数相关,本质上起源于热耗散过程,基于电容匹配原理很难完全消除回滞。与阻尼系数相关的热耗散随频率增大而急剧增加,因此负电容场效应晶体管并不适用于高频应用领域。该研究有助于深入理解HfO_(2)基体系中的负电容物理起源。Negative capacitance stabilized in HfO_(2)-based ferroelectric films offers a promising solution for low power-dissipation nanoscale electronics,however,its physical picture is still under intensive debate.Herein,the ferroelectric HfO_(2)/dielectric double layer system was modeled based on the Landau-Devonshire and Landau-Khalatnikov equations.Results show that the conventional quasi-static negative capacitance theory,which is rooted in the zero-field Gibbs free energy landscape and the quasi-static polarization-voltage curve,cannot capture the true polarization-voltage trajectory during the dynamic switching process.The negative capacitance observed in the ferroelectric HfO_(2)/dielectric system depends strongly on the evolution of the voltage dived by the dielectric layer and has a transient nature,which is at odds with the prediction of the quasi-static negative capacitance theory.Moreover,the emergence of hysteresis is ascribed to the thermal dissipation related to the damping parameter in the Landau-Khalatnikov equation,and it cannot be fully suppressed by the capacitance matching scenario.The thermal dissipation induced by the damping parameter is hugely enhanced with increasing frequency,which makes the high-frequency application of negative capacitance field-effect transistor rather impossible.This study provides an in-depth understanding on the underlying mechanism of the negative capacitance effect found in the HfO_(2)-related materials.

关 键 词：负电容 极化-电压曲线 回滞 吉布斯自由能 热耗散 氧化铪基铁电材料 

分 类 号：O484.3[理学—固体物理]