A method of manufacturing a semiconductor device forms a agglomeration-free
seed layer on the inner surface of a recessed portion so as to restrain
voids in a metal filled by the plating method. The method includes forming
a barrier metal layer on a surface of the recessed portion, forming a seed
layer on the barrier metal layer, and forming a metal filled in the
recessed portion by the plating method making use of the seed layer. The
method further includes retaining the water for 50 seconds or more, after
forming the barrier metal layer, in a chamber with a vacuum state set
therein other than the seed layer forming chamber.
