Comparative study of hydrogen- and deuterium- induced degradation of ferroelectric (Pb,La)(Zr,Ti)O3 capacitors using time of flight secondary ion measurement
Comparative study of hydrogen- and deuterium- induced degradation of ferroelectric (Pb,La)(Zr,Ti)O3 capacitors using time of flight secondary ion measurement
复制标题
使用飞行时间二次离子测量对氢和氘引起的铁电 (Pb,La)(Zr,Ti)O3 电容器的退化进行比较研究
DOI：
10.1109/tuffc.2016.2593585
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
and Rie Shishido
中科院分区：
文献类型：
--
作者：
Yoko Takada;Naoki Okamoto;Takeyasu Saito;Takeshi Yoshimura;Norifumi Fujimura;Koji Higuchi;Akira Kitajima;and Rie Shishido
用铂、铝：氧化锌(AZO)和锡：铟(ITO)为顶电极制备了铁电(Pb，La)(Zr，Ti)O_3(PLZT)电容器。在200℃、1Torr的3%H_2/BALANCE N_2或3%D_2/BALANER N_2环境中，对三种电容器进行了氢气或氢气诱导的退化研究。与AZO/PLZT/Pt和ITO/PLZT/Pt电容器相比，在H_2和D_2气氛中，45分钟后，所有电容器的剩余极化都有所降低，但在45分钟后，尽管铂/PLZT/铂电容器的初始剩余极化比AZO/PLZT/PT和ITO/PLZT/PT电容器的初始剩余极化大，但其剩余极化显著降低。飞行时间二次离子质谱仪显示，三种不同的电容器在氢退火后氢含量略有不同。与之相反，经过氘退火处理后，铂/PLZT/铂和AZO/PLZT/铂或ITO/PLZT/PT电容器的氘含量明显不同。对退火后的铂/PLZT/铂电容器的深度剖面分析表明，在铂/PLZT/铂电容器的PLZT层中，氘以共生形式存在，并且在铂底电极下也观察到了氢的积累。这一结果表明，氢在铂中的扩散远高于在PLZT中的扩散。AZO和ITO顶电极可以作为铁电薄膜的氢阻挡层。
Ferroelectric (Pb,La)(Zr,Ti)O3(PLZT) capacitors were fabricated with Pt, Al:ZnO (AZO), or Sn:In2O3(ITO) top electrodes. Hydrogen or deuterium-induced degradation was investigated for the three capacitors by annealing in a 3% H2/balance N2or 3% D2/balance N2ambient environment at 200 °C and 1 torr. The remnant polarization of all capacitors decreased after annealing in both H2and D2 ambient after 45 min, and the remnant polarization of the Pt/PLZT/Pt capacitor significantly decreased after 45-min annealing compared with that of the AZO/PLZT/Pt and ITO/PLZT/Pt capacitors, even though the initial remnant polarization for the Pt/PLZT/Pt capacitor was larger. Time-of-flight secondary ion mass spectrometry showed slight differences in hydrogen content for the three different capacitors after H2annealing. In contrast, the deuterium content of the Pt/PLZT/Pt and AZO/PLZT/Pt or ITO/PLZT/PT capacitors was significantly different after deuterium annealing. Deuterium depth profiles for the Pt/PLZT/Pt capacitor after annealing showed that deuterium conformally exists in the PLZT layer of the Pt/PLZT/Pt capacitor, and deuterium accumulation under the Pt bottom electrode was also observed. This result suggests that diffusion of deuterium in Pt was much higher than that in PLZT. AZO and ITO top electrodes could act as a hydrogen barrier layer for ferroelectric films.