The work aims to verify the thermal stability and diffusion-barrier performance of the 15-nm-thick AlCrTaTiZrRu/ (AlCrTaTiZrRu)N0.7 barrier layers. The 15-nm AlCrTaTiZrRu (3 nm)/(AlCrTaTiZrRu)N0.7 (12 nm) double-layer barrier layers were deposited on n-type Si (111) substrate by a DC magnetron-sputtering technology. Subsequently, a 50-nm-thick of Cu film was deposited on the top of the AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7 composite film, to obtain the Cu/AlCrTaTiZrRu/ (AlCrTaTiZrRu)N0.7/Si composite thin film samples. The samples were annealed in a vacuum-annealing furnace at 600-900 ℃ for 30 minutes to simulate the worst application environment. Field emission scanning electron microscopy (FE-SEM), X-ray diffractometer (XRD), energy spectrum analyzer (EDS), four-probe resistance tester (FPP), and atomic force microscope (AFM) were applied to characterize and analyze the surface morphology, phase composition, chemical composition, square resistance and roughness of the samples. The results indicated that the as-deposited AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7 films exhibited amorphous structure and were well bonded to Cu film and Si substrate. After annealing at 800 ℃, the Cu/AlCrTaTiZrRu/ (AlCrTaTiZrRu)N0.7/Si films system still exhibited a complete structure, no delamination occurred between the interface of the film structure, and the agglomeration of Cu particles on the surface was intensified. However, no Cu-Si compound was found on the surface of the Si substrate and Cu film, and the square resistance of the films was kept at a low value of 0.070Ω/sq. After annealing at 900 ℃, there was no interlayer separation and void phenomenon in the thin films system. Isolated large particles of Cu-Si compounds were formed on the surface of the Cu film, and the resistivity of the films increased significantly. The AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7 double-layer structure can still effectively inhibit the interdiffusion of Cu and Si after annealing at 800 ℃. Its amorphous structure enhances the thermal stability and diffusion-barrier of the Cu/HEA/HEAN0.7/Si system.