The influence of thin film fabrication process on ferroelectric properties and ferroelectric random access memories

薄膜制造工艺对铁电特性和铁电随机存取存储器的影响

• 批准号: 10450120
• 负责人: SHIOSAKI Tadashi
• 金额: $ 4.42万
• 依托单位: Nara Institute of Science and Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10450120/
• 关键词: Ferroelectric Thin Film; FRAM; MOCVD; Chemical Solution Deposition; Electron-Beam-Induced Reaction; Thermally Stimulated Current; Polarization Fatigue; Imprint; 強誘電体不揮発性メモリー; Pb(Zr,Ti)O_3; 分極反転疲労; 空間電荷; マイクロクラック

Ferroelectric thin films have been interesting materials because of FeRAM application. Therefore, ferroelectric thin films are fabricated by various preparation methods. However, the ferroelectric thin films obtained shows the peculiar properties such as the polarization fatigue, imprint and so on. We studied these phenomena, and obtained the knowledge about them.The thermally stimulated current (TSC) of the this films were examined. The peak of TSC of fatigued sample are obtained, revealing that the main origin of the polarization fatigue phenomena was the domain pinning caused by trapped charge carriers injected by polarization reversal. The internal bias field in the films were also investigated by pulse measurement. The PZT thin films obtained by a chemical solution deposition process exhibited a conspicuous initial voltage shift in the D-E hysteresis loop toward the negative-bias field. It was concluded that the origin of the voltage shift was an internal bias field due to asymmetric space-charge distribution induced by the natural alignment of spontaneous polarization during the cooling process. The internal bias field caused asymmetric depolarization at the zero-bias field.

由于使用Feram，铁电薄膜一直是有趣的材料。因此，铁电薄膜是通过各种制备方法制造的。然而，获得的铁电薄膜显示了诸如极化疲劳，烙印等特性。我们研究了这些现象，并获得了有关它们的知识。检查了该膜的热刺激电流（TSC）。获得了疲劳样品的TSC峰，表明极化疲劳现象的主要起源是由偏振反转注入的陷阱荷载体引起的域固定。还通过脉冲测量研究了膜中的内部偏置场。通过化学溶液沉积过程获得的PZT薄膜在D-E磁滞回路向负偏置场中表现出显着的初始电压移动。得出的结论是，由于在冷却过程中自然极化引起的自然对准引起的不对称空间充电分布，电压偏移的起源是一个内部偏置场。内部偏置场在零偏置场处引起不对称的地去极化。

项目成果

T.Shiosaki et al: "Thermally Stimulated Current and Polarization in Pb(Zr, Ti) OィイD23ィエD2 Thin Films"Jpn. J. Appl. Phys.. 37. 5137-5140 (1998)

T. Shiosaki 等人：“Pb(Zr, Ti) O23D2 薄膜中的热刺激电流和极化”Jpn. J. Appl. 37. 5137-5140 (1998)

T. Shiosaki et al.: "Thermally Stimulated Current and Polarization in Pb (Zr, Ti) O_3 Thin Film"Jpn. J. Appl. Phys.. 37. 5137-5140 (1998)

T. Shiosaki 等：“Pb(Zr,Ti)O_3 薄膜中的热刺激电流和极化”Jpn。

S. Okamura et al.: "Conspicuous Voltage Shift of D-E Hysterias Loop and Asymmetric Depolarization in Pb-Based Ferroelectric Thin Films"Jpn. J. Appl. Phys.. 38. 5364-5367 (1999)

S. Okamura 等人：“Pb 基铁电薄膜中 D-E 磁滞环的显着电压偏移和不对称去极化”Jpn。

塩嵜忠 他: "不揮発性メモリー用強誘電薄膜の分極特性に及ぼす空間電荷の影響"マテリアル インテグレーション. 12. 25-30 (1999)

Tadashi Shiozaki 等人：“空间电荷对非易失性存储器铁电薄膜极化特性的影响”Materials Integration 12. 25-30 (1999)。

S.Okamura et al: "Conspicuous Voltage Shift of D-E Hysteresis Loop and Asymmetric Depolarization in Pb-Based Ferroelectric Thin Films"Jpn. J. Appl. Phys.. 38. 5364-5367 (1999)

S.Okamura 等人：“Pb 基铁电薄膜中 D-E 磁滞回线的显着电压偏移和不对称去极化”Jpn。