Advancement of large-scale integrated interconnect structure requires an ultra-thin and uniform diffusion barrier
layer between Cu interconnect and insulating layers. As a promising alternative barrier to the conventional
Ta/TaN, the self-forming barrier layer from the CuMnTi alloy layer was investigated in this work. In order to
achieve the self-forming barrier layer, the CuMnTi alloy layer first was deposited on SiO2 substrate by magnetron
sputtering. Second, the alloying elements were driven and migrated to the interface, and moreover, reacted with
SiO2 to form the self-forming barrier layer. The self-forming barrier layer has a thickness of about 5 nm. The annealing
leads to an obvious decrease of resistivity from 50.10 μΩ cm to 4.23 μΩ cm for the CuMnTi alloy layer. The
self-forming barrier can improve the adhesion of Cu interconnect layer and effectively prevent element diffusion
between Cu interconnect and insulating SiO2 substrate.
© 2016 Elsevier B.V. All rights reserved.
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