Fabrication and thermal stability of AlCrTaTiNi/(AlCrTaTiNi)N bilayer diffusion barrier

The (AlCrTaTiNi)N and AlCrTaTiNi/(AlCrTaTiNi)N thin films were deposited on Si substrates as copper interconnects diffusion barriers by magnetron sputtering methods. The phase structure, phase composition and thermal stability at high temperature were investigated by XRD, EDS and SEM in this work, respectively. The results indicate that the gap could be observed between Cu and (AlCrTaTiNi)N layers when the samples were annealed at 500°C for 30 min, and the Cu film fall off at 700°C under visual conditions. The bonding properties of Cu and (AlCrTaTiNi)N layers can be improved by inserting a AlCrTaTiNi layer. The XRD patterns, SEM cross-sectional micrographs and sheet resistance data show that the AlCrTaTiNi/(AlCrTaTiNi)N bilayers is stable up to 800°C. © Copyright.