METHOD FOR DEPOSITING A COPPER SEED LAYER ONTO A BARRIER LAYER AND COPPER PLATING BATH

摘要

The present invention relates to a method for providing a copper seed layer on top of a barrier layer wherein said seed layer is deposited onto said barrier layer from an aqueous electroless copper plating bath comprising a water-soluble source for Cu(II) ions, a reducing agent for Cu(II) ions, at least one complexing agent for Cu(II) ions and at least one source for hydroxide ions selected from the group consisting of RbOH, CsOH and mixtures thereof. The resulting copper seed layer has a homogeneous thickness distribution and a smooth outer surface which are both desired properties.

主权项

1. A method for providing a copper seed layer on top of a barrier layer comprising, in this order, the steps of
(i) providing a substrate comprising at least on a portion of the outer surface a barrier layer, (ii) contacting said substrate with an aqueous electroless copper plating bath which comprises
a. a water-soluble source for Cu(II) ions,b. a reducing agent for Cu(II) ions,c. at least one complexing agent for Cu(II) ions andd. at least one source for hydroxide ions selected from the group consisting of RbOH, CsOH and mixtures thereof.