金属热处理 ›› 2021, Vol. 46 ›› Issue (9): 216-222.DOI: 10.13251/j.issn.0254-6051.2021.09.039

• 表面工程 • 上一篇    下一篇

AlCrTaTiZrV高熵合金氮化物扩散阻挡层的制备及其热稳定性

李荣斌1,2, 李珂1, 蒋春霞2, 张如林2   

  1. 1.上海理工大学 材料科学与工程学院, 上海 200093;
    2.上海电机学院 材料学院, 上海 201306
  • 收稿日期:2021-05-11 出版日期:2021-09-25 发布日期:2021-12-09
  • 作者简介:李荣斌(1969—),男,教授,博士,主要研究方向为高熵合金, E-mail:617685867@qq.com
  • 基金资助:
    国家自然科学基金面上项目(51671125);上海大件热制造工程技术研究中心(18DZ2253400)

Preparation and thermal stability of AlCrTaTiZrV-nitride diffusion barrier layer

Li Rongbin1,2 , Li Ke1, Jiang Chunxia2, Zhang Rulin2   

  1. 1. School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;
    2. School of Materials, Shanghai Dianji University, Shanghai 201306, China
  • Received:2021-05-11 Online:2021-09-25 Published:2021-12-09

摘要: 为研究氮气含量的变化对AlCrTaTiZrV高熵合金薄膜性能的影响,检验在最佳氮气含量下厚度为15 nm的(AlCrTaTiZrV)N扩散阻挡层的热稳定性。采用直流磁控溅射设备在N型Si(111)基底上溅射不同氮气含量的高熵合金氮化物;选取最佳氮气含量为制备条件,在硅基底上沉积15 nm厚的AlCrTaTiZrVN10高熵合金氮化物为扩散阻挡层,并在阻挡层顶部沉积50 nm厚度的Cu膜,最终形成Si/AlCrTaTiZrVN10/Cu三层堆叠结构。利用真空退火炉将Si/AlCrTaTiZrVN10/Cu薄膜体系在500 ℃下进行不同时间的退火处理,用以模拟恶劣的工作环境。利用场发射扫描电子显微镜(FESEM)、原子力显微镜(AFM)、X射线衍射仪(XRD)及四探针电阻测试仪(FPP)对试样的表面形貌、粗糙度、物相组成及方块电阻和进行表征。试验结果为:当氮气含量低于10%时,高熵合金氮化物薄膜为非晶结构。当氮气含量为20%时,高熵合金氮化物薄膜呈现FCC结构,并随着氮气含量的增加,薄膜的结晶性得到提高。薄膜表面的粗糙度在氮气含量为10%时最低,Ra仅为0.124 nm。三层堆叠结构500 ℃退火8 h后,Cu表面发生团聚,薄膜的方阻维持在较低的0.070 Ω/□,且并未发现Cu-Si化合物。厚度为15 nm的非晶结构AlCrTaTiZrVN10薄膜在500 ℃退火8 h后,依旧可以抑制Cu的扩散,表现出了优异的热稳定性及扩散阻挡性能。

关键词: 高熵合金, 扩散阻挡层, 氮化物薄膜, 非晶结构, 退火, 热稳定性

Abstract: The work aimed to study the effect of different nitrogen flow rates on the properties of AlCrTaTiZrV high-entropy alloy nitride films and to examine the thermal stability of (AlCrTaTiZrV)N diffusion barrier layer with a thickness of 15 nm under the optimum nitrogen content. The (AlCrTaTiZrV)N high-entropy alloy nitride films were synthesized by reactive magnetron sputtering under different nitrogen flow. A 15 nm amorphous AlCrTaTiZrVN10 film was prepared on single crystal silicon as a single-layer barrier material for Cu interconnection. A 50 nm-thick Cu film was deposited on the surface of the AlCrTaTiZrVN10 film to obtain the Si/AlCrTaTiZrVN10/Cu film system. To assess its thermal stability, Si/AlCrTaTiZrVN10/Cu structure was annealed at 500 ℃ in high vacuum for various time to simulate real working conditions. The surface morphology, roughness, phase composition and sheet resistance of the specimens were characterized by means of the field emission scanning electron microscopy (FE-SEM), atomic force microscope (AFM), X-ray diffractometer (XRD) and four-point probe (FPP), respectively. The results show that the AlCrTaTiZrV high-entropy alloy thin film is amorphous structure when the nitrogen flow rate is less than 10%. When the nitrogen content is 20%, the high-entropy alloy nitride film presents FCC structure and the crystallinity of the film is improved with the increase of nitrogen content. When the nitrogen flow rate is 10%, the roughness is the lowest of only 0.124 nm. After annealed at 500 ℃ for 8 h, the grain size increases significantly. However, the sheet resistance of the films remain at a low value of 0.070 Ω/□, and no Cu-Si compound is formed. The amorphous structure of 15 nm AlCrTaTiZrVN10 high-entropy alloy nitride film can effectively prevent the diffusion of Cu after annealing at 500 ℃ for 8 h, showing excellent thermal stability and good diffusion barrier properties on Cu.

Key words: high-entropy alloy, diffusion barrier layer, nitride film, amorphous structure, annealing, thermal stability

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