IMPROVEMENT OF FATIGUE PROPERTIES IN FERROELECTRIC NONVOLATILE MEMORY PREPARED BY PULSED LASER ABLATION

脉冲激光烧蚀制备的铁电非易失性存储器疲劳性能的改善

• 批准号: 06650010
• 负责人: MORIMOTO Akiharu
• 金额: $ 1.28万
• 依托单位: KANAZAWA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06650010/
• 关键词: PULSED LASER ABLATION; FERROELECTRIC NON-VOLATILE MEMORY; LEAD-ZIRCONATE-TITANATE; Ni-ALLOY ELECTRODE; TITANIUM ALUMINUM NITRIDE; MAGNESIA BUFFER LAYER; SWITCHED CHARGE; FATIGUE RESISTANCE FOR SWITCHING; マグネシア基板; 窒化チタンアルミ(TiA1N)電極; P-E履歴曲線; C-V

For metal/ferroelectrics/metal (MFM) memory, ferroelectric lead-zirconate-titanate (Pb (Zr_<0.52>Ti_<0.48>) O_3 : PZT) thin-film capacitors were fabricated by ArF pulsed laser ablation (PLA) using Ni-alloy electrodes on oxidized (100) silicon. The fatigue test revealed that the increase in the frequency both for acceleration and measurement of switching pulse increases the life of polarization reversal while it decreases the switched charge density Q_<SW>. At 50 kHz, Q_W keeps the initial value even after switching above 10^<10> cycles. The measurement frequency dependence of Q_<SW> suggests that a homogeneous fatigue takes place irrespective of fast and slow domains and additional layrs of a low dielectric constant are probably formed in the ferroelectric-metal interface.The effect of various electrodes on the ferroelectric properties of PZT films through the film structure is also presented. These experiments revealed that there is no simple correlation between the film structure and the fatigue resistance. The fatigue resistance is, however, found to be improved primarily by decreasing Q_<SW>, although the correlation shows some ambiguity. For examining the fatigue properties, titanium-aluminum-nitride (Ti-Al-N ; TAN) electrode films were proposed for PZT thin-film capacitors. Capacitors with rather randomly oriented PZT films on the TAN/(100) Si did not show a ferroelectric hysteresis loop, but the capacitor with preferentially [100] -oriented PZT film on the TAN/(100) MgO did. This suggests that a TAN-electrode film was grown on (100) MgO with a high oxidation resistance at the high temperature employed for ferroelectric oxide preparation.For metal ferroelectrics/insulator/semiconductors-(MFIS-) FET memory, PZT/MgO/(100) Si structure was proposed. The PZT film obtained was found to be highly oriented perovskite PZT film with a ferroelectric P-E hysteresis.

为了实现金属/铁电/金属(MFM)存储，采用ArF脉冲激光烧蚀方法，在氧化(100)硅片上制备了铅-锆钛(0.52&gt；0.48&gt；)O_3：PZT铁电薄膜电容器。疲劳试验表明，加速频率和开关脉冲测量频率的提高延长了极化反转寿命，但降低了开关电荷密度Q&lt；Sw&gt；在50 kHz时，Q_W即使在切换到10^&lt；10&gt；个周期之后仍保持初始值。Q&lt；Sw&gt；测量频率的关系表明，无论快、慢，都会发生均匀的疲劳，在铁电-金属界面上可能会形成额外的低介电常数层，并通过薄膜结构讨论了不同电极对PZT薄膜铁电性能的影响。这些实验表明，薄膜结构与抗疲劳性能之间并不存在简单的关系。然而，发现疲劳抗力主要是通过降低Q&lt；Sw&gt；来改善的，尽管相关性显示出一些模糊。为了测试PZT薄膜电容器的疲劳性能，提出了钛铝氮化物(Ti-Al-N；TaN)电极薄膜。在Tan/(100)Si上PZT薄膜随机取向的电容器没有表现出铁电磁滞回线，而在Tan/(100)MgO上优先取向PZT薄膜的电容器出现了铁电磁滞回线。这表明在高温下具有较高抗氧化性的氧化镁衬底上生长了一层TaN电极薄膜用于铁电氧化物的制备。对于金属ferroelectrics/insulator/semiconductors-(MFIS-)场效应管存储器，提出了PZT/MgO/(100)Si结构。得到的PZT薄膜为高度取向的钙钛矿型PZT薄膜，具有铁电P-E磁滞。

项目成果

T.Shimizu: "Laser Ablation Deposition of Oxide Films" Extended Abstract of 12th Yokohama 21st Century Forum on Fullerens and Laser Processing. (1996)

T.Shimizu：“氧化膜的激光烧蚀沉积”第十二届横滨 21 世纪富勒伦和激光加工论坛的扩展摘要。

A.Morimoto et al.: "Preparation of Ti-A1-N Electrode Films by Pulsed Laser Ablation for Lead-Zirconate-Titanate Film Capacitors" Jpn.J.Appl.Phys.Vol.35. L227-L230 (1996)

A.Morimoto 等人：“通过脉冲激光烧蚀制备钛酸铅薄膜电容器的 Ti-Al-N 电极薄膜”Jpn.J.Appl.Phys.Vol.35。

T.Shimizu et al.: "Laser Ablation Deposition of Oxide Films" Extended Abstract of 12th Yokohama 21st Century Forum on Fullerens and Laser Processing. (1996)

T.Shimizu 等人：“氧化膜的激光烧蚀沉积”第 12 届横滨 21 世纪富勒伦和激光加工论坛的扩展摘要。

A.Masuda: "Preparation and Crystallographic Characterizations of Highly Oriented Pb (Zr_<0.5>Ti_<0.48>) O_3 Films and MgO Buffer Layrs on (100) GaAs and (100) Si by Pulsed Laser Ablation" J.of Crystal Growth. Vol. 158. 84-88 (1996)

A.Masuda：“通过脉冲激光烧蚀在 (100) GaAs 和 (100) Si 上制备高度取向的 Pb (Zr_<0.5>Ti_<0.48>) O_3 薄膜和 MgO 缓冲层并进行晶体学表征”J.of Crystal Growth。

A.Morimoto et al.: "Fatigue Behavior in Lead-Zirconate-Ti tanate Thin-Film Capacitors Prepared by Pulsed Laser Ablation on Ni-Alloy Electrodes" Jpn.J.Appl.Phys.Vol.34. 4108-4113 (1995)

A.Morimoto 等人：“通过脉冲激光烧蚀镍合金电极制备的铅-锆酸钛酸铅薄膜电容器的疲劳行为”Jpn.J.Appl.Phys.Vol.34。