物理学报2017，Vol.66Issue(8)：318-326,9.DOI:10.7498/aps.66.087301
基于Ni电极和ZrO2/SiO2/ZrO2介质的MIM 电容的导电机理研究
Conduction mechanisms of MIM capacitors with ZrO2/SiO2/ZrO2 stacked dielectrics and Ni electro des
摘要
Abstract
The electrical characteristics of Ni electrode-based metal-insulator-metal (MIM) capacitors have been investigated with atomic layer deposited ZrO2/SiO2/ZrO2 symmetric stacked-dielectrics. When the thickness of the stacked-dielectrics is fixed at 14 nm, the resulted capacitance density decreases from 13.1 fF/m2 to 9.3 fF/m2, and the dissipation factor is reduced from 0.025 to 0.02. By comparison of current-voltage (I-V ) curves of different MIM capacitors, it is found that the leakage current density in the high voltage region decreases gradually with the increasing thickness of SiO2, and it does not exhibit clear change in the low voltage region. Meanwhile, the capacitors show different conduction behaviors under positive and negative biases with increasing the thickness of SiO2 from 0 to 2 nm. Under the positive bias, different I-V characteristics are demonstrated at high and low electric fields, respectively. However, a single I-V characteristic is dominant under the negative bias. Further, the conduction mechanisms of the capacitors are investigated under the electron bottom and top injection modes, respectively. It is found that the Poole-Frenkel emission and the trap-assisted tunneling are dominant in the high and low field regions, respectively, for the electron bottom injection; however, the trap-assisted tunneling is dominant in the whole field region for the electron top injection. These are attributed to the formation of a thin NiOx interfacial layer between the Ni bottom-electrode and the ZrO2 dielectric layer, as well as the existence of both deep and shallow level traps (0.9 and 2.3 eV) in the ZrO2 dielectric. Therefore, the level trap plays a key role in the electron conduction in the MIM capacitor under different electron injection modes and different electric fields.关键词
金属-绝缘体-金属电容/导电机理/ZrO2/SiO2/ZrO2叠层介质/Ni电极Key words
metal-insulator-metal capacitor/conduction mechanism/ZrO2/SiO2/ZrO2 stacked-dielectric/Ni electrodes引用本文复制引用
刘骐萱,王永平,刘文军,丁士进..基于Ni电极和ZrO2/SiO2/ZrO2介质的MIM 电容的导电机理研究[J].物理学报,2017,66(8):318-326,9.基金项目
国家02科技重大专项(批准号:2015ZX02102-003)资助的课题. Project supported by the National Key Technologies R&D Program of China (Grant No.2015ZX02102-003). （批准号:2015ZX02102-003）
