Effect of Nitrogen Content in TaN[sub x] (x = 0-1) Barrier Substrates on Electroless Copper Deposition

Electroless copper deposition on barrier films was investigated in terms of nitrogen flow rates. Field-emission scanning electron microscopy micrographs of the electroless copper deposition on barrier and palladium-activated barrier films showed that the density of the copper aggregates and of palladium nuclei increased with increasing nitrogen flow rate. As a result, the more uniform and excellent electroless copper deposition was acquired as the nitrogen flow rate increases. Plan-view transmission electron microscopy micrographs of palladium activated for 5 s showed that palladium nuclei formed on grain boundaries, especially on grain edges of barrier films in the initial stage of palladium activation.