Preparation and thermal stability of VNbMoTaWCo-nitride diffusion barrier layer

doi:10.13251/j.issn.0254-6051.2022.06.037

Abstract

Abstract: VNbMoTaWCoN_x films (x=N₂ flow rate) were prepared by DC magnetron sputtering in different N₂ flow parameter. At N₂ flow ratio of 20%, a Cu/VNbMoTaWCoN₂₀/Si triple-layer stack structure was prepared by depositing a 15 nm thick VNbMoTaWCoN₂₀ film on the cleaned silicon substrate and depositing a 50 nm thick Cu film on the top. The sheet resistance, phase structure, roughness and surface morphology of the Cu/VNbMoTaWCoN₂₀/Si structure samples before and after annealing at 500 ℃ were analyzed and characterized by four probe resistance tester (FPP), X-ray diffractometer (XRD), atomic force microscope (AFM), field emission scanning electron microscope (SEM), and then the thermal stability and diffusion barrier properties of the VNbMoTaWCoN₂₀ film were studied. The results indicate that when the N₂ flow ratio is 20%, the VNbMoTaWCoN₂₀ film before annealing is amorphous with some locally dispersed nanocrystals, and with flat and smooth film surface, with the best density and the smallest roughness. After the Cu/VNbMoTaWCoN₂₀/Si triple-layer stack structure is annealed at 500 ℃ for 8 h, though agglomeration occurs on the surface of the Cu film, but no Cu-Si compound is found, and the sheet resistance of the film is still maintained at a low value 0.065 Ω/sq. The amorphous structured VNbMoTaWCoN₂₀ film as diffusion barrier layer annealed at 500 ℃ for 8 h showes excellent thermal stability and diffusion barrier properties.

Key words: high-entropy alloy nitride film, thermal stability, diffusion barrier layer, annealing, DC magnetron sputtering

CLC Number:

TG174.4

Li Rongbin, Zhang Xia, Jiang Chunxia. Preparation and thermal stability of VNbMoTaWCo-nitride diffusion barrier layer[J]. Heat Treatment of Metals, 2022, 47(6): 196-201.

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