Microstructure And Properties Of Magnetron Sputtering (AlCrFeMoZr)N_X Thin Films

With the development of chip manufacturing technology,the size of integrated circuits has gradually decreased.The diffusion barrier layer is used to prevent the diffusion of copper and neutral molecules in the air into the low-k dielectric layer,reduce the time delay（RC）and increase the bonding between electroplated copper and low-k dielectric film.The diffusion barrier layer is expected to have continuously improved performance in ultra-thin,low resistivity,high thermal stability and good adhesion.High entropy alloys（HEAs）show the effects of slow diffusion and lattice distortion.The HEA films are expected to possess high thermal stability,and have great application prospects in the field of diffusion barrier layer.In this paper,AlCrFeMoZr and（AlCrFeMoZr）N_Xthin films were deposited on P-type Si（100）substrate by magnetron sputtering.The surface morphology,crystal structure,composition and square resistance of the films were analyzed by atomic force microscopy（AFM）,X-ray diffrotometer（XRD）,scanning electron microscopy（SEM）,electron energy spectroscopy（EDS）,X-ray photoelectron spectroscopy（XPS）and four-probe resistance tester.Furthermore,the（AlCrFeMoZr）N_X/AlCrFeMoZr（HEAN_X/HEA）double-layer diffusion-resistant films were prepared.The diffusion resistance of the Si/HEAN_X/HEA/Cu multi-layers were examined by high temperature annealing.The experimental results show that the HEA films prepared at different bias pressures and deposition temperatures are amorphous.The thermal stability of the films can be improved by adding N atoms into the films.The crystallographic structure of the HEAN_Xfilms were tuned by adjusting the N₂/（N₂+Ar）flow ratio（R_N）.the films prepared by R_Nless than 30%was amorphous,and 30%<R_N<40%resulted in weak crystallization of the films.Severe lattice distortion hinders the grain growth of the films.A series of HEAN_X/HEA/Cu multi-layers was prepared on Si,by tunning the composition of the HEAN_Xlayer with R_Nof 10%,20%,30%,40%and 50%.The films were annealed at600℃～900℃.The results show that the multi-layers prepared with R_N=40%possesses the best thermal resistance.It does not fail after annealing at 900℃ for 1h.