| abstract |
A method of filling blind vias with metallic copper comprising etching a substrate to form blind vias having an inner wall, forming a seed layer for cladding the inner wall of the blind vias, and performing an electrical copper plating treatment with the seed layer as an electrode in one A copper sulphate electrolyte, such that the blind vias are filled with metallic copper, the copper sulphate electrolyte containing the following components (a) and (b): (a) a polyether containing at least five ether oxygen atoms in one molecule; and (b) one or more of the substances represented by the following formulas (I), (V) to (X): R 1 -S- (CH 2 O) n -R 2 -SO 3 M (I) wherein R 1 is a hydrogen atom, - (S) n - (CH 2 O) n -R 2 -SO 3 M or -CS n - (CH 2 O) n -R 2 -SO 3 M, R 2 is an alkylene group with 3 to 8 carbon atoms, M is a hydrogen atom or an alkaline metal and n is 0 or 1, M-SO 3 - (CH 2 ) a -S- (CH 2 ) b -SO 3 -M (V) where a = 3 to 8, b = 3 to 8, M is hydrogen or an alkaline metal element; |