Low Temperature Oxidation of Ultra-High Purity Metals and Stoichiometry Control of Oxide Films

超高纯金属的低温氧化及氧化膜的化学计量控制

• 批准号: 17360366
• 负责人: ISSHIKI Minoru
• 金额: $ 10.06万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17360366/
• 关键词: Zirconium; Hafnium; Copper; Thin Film; Oxidation; 誘電特性

To clarify the mechanism of surface oxidation of metals is very important to stabilize the metal surface. However, especially, at low temperatures, experimental result is few because of the difficulty of experiments to follow the nano-scale oxidation. Furthermore, nano-scale metal oxide films have been used widely in many electronic devises. Although their electrical properties should be dependent on the quality of the oxide film, such as point defects caused by the deviation from the stoichiometric composition, impurities, structural defects, and so on, there has been no systematic study. In this research project, the effects of impurities, structural defects and native defects on the electrical properties of nano-scale Zr oxide films in addition to clarifying the low temperature oxidation of Cu to establish the guideline to control the quality of nano-scale oxide films.Single-crystal-copper ((100), (110), (111)) with the purity of 5N and poly-crystal copper specimens with different p … More urities of 2 N, 4 N and 6 N were oxidized at 315 ~ 378 K under 0.1 MPa of oxygen partial pressure. The oxide thickness was measured by in-situ spectroscopic ellipsometry. It was confirmed that oxidation rate of (100) was the highest, and those of (110) and (111) were similar. In the case of poly-crystal, the oxidation of 6 N-copper was the fastest. It is found that the low temperature oxidation kinetics were the inverse-logarithmic law below 5 nm, the cubic law from 5 nm to 25 nm and the parabolic law over 25 nm. In addition the activation energy was estimated and the similar value to that in Cabrera-Mott theory was obtained.ZrO_2 layers were prepared using a two-step method, i.e., fabrication of pure Zr films by negatively biased ion beam deposition system (IBD), and oxidation of pure Zr films at 473 K for 60 min under 0.1 Mpa O_2 atmosphere, and the effect of Zr film quality on the electrical properties of ZrO_2 layer was investigated. In order to to clarify the influence of purity and structural defects, the purified Zr target was used and Zr films were deposited on the Pt/Si or Si substrate by means of ion beam deposition with applying the negative substrate bias voltage of - 50V. To control the native oxide concentration, Zr films were oxidized with/without UV light irradiation (λ=193 nm, Deep UV lamp). Characterization of Zr and ZrO_2 films were carried out using XRD, FE-SEM, HRTEM and XPS. Capacitance-voltage (C-V) and current-voltage (I-V) measurements were carried out using MIM structure or MOS structure. It was found that the decrease of impurity, the structural defects and the native defects remarkably increase the dielectric constant and decrease the leakage current. Less

阐明金属表面氧化机理对稳定金属表面具有重要意义。然而，特别是在低温下，由于实验难以跟踪纳米尺度的氧化，实验结果很少。此外，纳米尺度的金属氧化物薄膜在许多电子器件中得到了广泛的应用。虽然它们的电性能应取决于氧化膜的质量，如偏离化学计量组成引起的点缺陷、杂质、结构缺陷等，但目前还没有系统的研究。本研究旨在探讨杂质、结构缺陷和本征缺陷对纳米Zr氧化物薄膜电学性能的影响，并阐明Cu的低温氧化机理，为纳米Zr氧化物薄膜的质量控制提供依据。采用高纯5 N单晶Cu（（100），（110），（111））和不同掺杂浓度的多晶Cu样品，对纳米Zr氧化物薄膜的电学性能进行了研究。结果表明：（100），（110），（111）单晶Cu（100）和（110）单晶Cu（110）样品的电学性能优于（110）单晶Cu（110）和（111）单晶Cu（110）样品，（110）单晶Cu（110）样品的电学性能优于（110）单晶Cu（110）样品。 ...更多信息 在315 ~ 378 K、0.1 MPa氧分压下，2N、4 N和6 N的氧化速率分别为1.25 × 10 - 4和1.25 × 10 - 4 × 10 - 4。氧化物厚度通过原位光谱椭圆偏振法测量。结果表明，（100）的氧化速率最高，（110）和（111）的氧化速率相近。在多晶的情况下，6 N-铜的氧化最快。结果表明，在5 nm以下，低温氧化动力学符合反对数规律;在5 ~ 25 nm范围内，低温氧化动力学符合立方规律;此外，还估算了ZrO_2薄膜的活化能，得到了与Cabrera-Mott理论近似的活化能。采用负偏压离子束沉积系统（IBD）制备了纯Zr薄膜，并在473 K、0.1 Mpa O_2气氛下氧化60 min，研究了Zr膜质量对ZrO_2层电学性能的影响。为了明确纯度和结构缺陷的影响，使用纯化的Zr靶，并通过离子束沉积在Pt/Si或Si衬底上沉积Zr膜，施加负衬底偏压为-50V。为了控制自然氧化物浓度，在有/没有UV光照射（λ=193 nm，深UV灯）的情况下氧化Zr膜。用XRD、FE-SEM、HRTEM和XPS对Zr和ZrO_2薄膜进行了表征。电容-电压（C-V）和电流-电压（I-V）测量使用MIM结构或MOS结构进行。结果表明，杂质含量的减少、结构缺陷和本征缺陷的存在显著提高了介电常数，降低了漏电流。少

项目成果

Thickness dependence of electrical resistivity for Cu films

铜膜电阻率的厚度依赖性

• 发表时间: 2006
• 作者: Kouji Mimura J.-W. Lim;G.-S. Choi;Minoru Isshiki;藤田健資;Kouji Mimura;M. Isshiki;M. Isshiki;Jae-Won Lim;J.-W. Lim;J. -W. Lime;J. -W. Bae;裴俊佑;J. -W. Lim;J. -W. Bae;朱永福;Y. F. Zhu;J.-W. Lim
• 通讯作者: J.-W. Lim

Effect of substrate bias voltage on the microstructure and electrical properties of Pt films deposited by ion beam deposition

衬底偏压对离子束沉积Pt薄膜微观结构和电学性能的影响

• 发表时间: 2006
• 作者: Kouji Mimura J.-W. Lim;G.-S. Choi;Minoru Isshiki;藤田健資;Kouji Mimura;M. Isshiki;M. Isshiki;Jae-Won Lim;J.-W. Lim;J. -W. Lime;J. -W. Bae
• 通讯作者: J. -W. Bae

酸素雰囲気中における単結晶Cuの低温酸化挙動

单晶Cu在氧气气氛中的低温氧化行为

• 发表时间: 2007
• 作者: Kouji Mimura J.-W. Lim;G.-S. Choi;Minoru Isshiki;藤田健資
• 通讯作者: 藤田健資

Concentrations change of impurities in thin films by applying negative substrate bias voltage

施加负基板偏压时薄膜中杂质浓度的变化

• 发表时间: 2005
• 作者: J. -W. Lim

Interpretation of dominant impurities in Cu films by SIMS and GDMS

通过 SIMS 和 GDMS 解释铜膜中的主要杂质

• 发表时间: 2005
• 期刊: Jpn.J.Appl.Phys. 44・1
• 作者: Keiichi;N.;Ishihara;Fumie;Kubo;Kohei;Irie;Kazuyoshi;Shichi;Eiji;Yamasue;Hideyuki;Okumura;J.-W.Lim
• 通讯作者: J.-W.Lim