The work aims to prepare a 15 nm (AlCrTaTiZrMo)N senary high-entropy alloy nitride film and characterize the diffusion barrier properties of the film. The (AlCrTaTiZrMo)N high-entropy alloy nitride film was deposited on single crystal silicon by direct current magnetron sputtering equipment. 150 nm of Cu was deposited on the film to form a Cu/(AlCrTaTiZrMo)N/Si structure. The structure was then annealed at 600 ℃ for different time. X-ray diffractometry (XRD), four-point probe (FPP), atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) were used to study the film composition and the effect of annealing time on the microstructure, surface morphology and sheet resistance of the film to evaluate the diffusion barrier properties. The film had a good adhesion to the substrates Si and Cu. The as-deposited film was amorphous and the surface was smooth and flat with a low value of sheet resistance. After annealed at 600 ℃ for 1 h, the film was still amorphous, but the surface became rough. With the increase of annealing time, some micro-nanocrystals appeared in the structure after annealing for 5 h, most of which were still amorphous, and the surface roughness increased. After annealing for 7 h, the structure was still amorphous and the nanocrystalline structure was encapsulated and some island-like grains were formed on the surface of Cu. The sheet resistance value was still low and no Cu-Si compound was formed. After annealing for long time, (AlCrTaTiZrMo)N high-entropy alloy nitride film still had good diffusion barrier properties on Cu. The amorphous inclusion nanocrystalline structure of 15 nm (AlCrTaTiZrMo)N high-entropy alloy nitride film after annealing at 600 ℃ after 7 h can eff-ectively block the diffusion of Cu, thus showing excellent thermal stability and diffusion barrier performance after prolonged annealing.