Copper plating bath composition

1. An aqueous acidic copper electroplating bath comprising a source of copper ions, an acid and at least one ureylene polymer selected from polymers according to Formulae (I), (II) and (III)

wherein A represents a unit derived from a diamino compound of the following Formulae (IV) and/or (V)

R 1 , R 2 , R 5 , and R 6 are independently selected from the group consisting of substituted or unsubstituted hydrocarbon residues with 1 to 10 carbon atoms, and —CH 2 CH 2 (OCH 2 CH 2 ) a —OH, wherein a is an integer from 0 to 4,

R 3 and R 4 are independently selected from the group consisting of (CH 2 ) p , wherein p is an integer from 2 to 12, and a —[CH 2 CH 2 O] m —CH 2 CH 2 — group, wherein m is an integer from 1 to 40,

Z may be the same or different and represents O or S,

x and y may be the same or different and are an integer selected from 1, 2 and 3

wherein A′ represents a unit derived from a diamino compound of the following Formulae (VI)

wherein R 7 and R 8 are independently selected from the group consisting of hydrogen, a substituted or unsubstituted hydrocarbon residue with 1 to 16 carbon atoms, linear or branched alkyl, hydroxyethyl or —CH 2 CH 2 (OCH 2 CH 2 ) a —OH, wherein a is an integer from 1 to 4, substituted or unsubstituted alkaryl, alkhetaryl, allyl or propargyl and

wherein L is a divalent residue, which is selected from the group consisting of —(CH 2 ) s —, wherein s is an integer from 1 to 12,

—CH 2 —CH(OH)—CH 2 —, —[CH 2 O] q —CH 2 CH 2 —, —[CH 2 CH 2 O] q —CH 2 CH 2 —,

—CH 2 —CH(SH)—CH 2 —, and —[CH 2 S] q —CH 2 CH 2 —, —[CH 2 CH 2 S] q —CH 2 CH 2 — wherein q is an integer from 1 to 40,

—CH 2 —CH(OH)—CH 2 —R9-CH 2 —CH(OH)—CH 2 — wherein R 9 is selected from the group consisting of a substituted or unsubstituted hydrocarbon residue, —O— CH 2 CH(OH)—CH 2 O— and —O—[CH 2 CH 2 O] q —CH 2 O—, wherein q is an integer from 1 to 40, and —CH 2 CH(OH)CH 2 —;

wherein the single units A may be the same or different,

wherein the single units A′ may be the same or different

wherein the single units L may be the same or different,

wherein n represents an integer from 1 to 40, and

wherein the ureylene polymers according to Formulae (I), (II) and (III) have an amino residue at both ends and wherein said aqueous acidic copper electroplating bath is essentially free of zinc ions, wherein the concentration of the ureylene polymer according to Formulae (I), (II) and (Ill) ranges from 0.001 mg/l to 200 mg/l and wherein the aqueous acidic copper electroplating bath has a pH value of ≦1.

2. The aqueous acidic copper electroplating bath according to claim 1 wherein R 1 , R 2 , R 5 and R 6 are independently selected from the group consisting of methyl, ethyl, hydroxyethyl, and —CH 2 CH 2 (OCH 2 CH 2 ) a —OH, and wherein a is an integer from 1 to 4.

3. The aqueous acidic copper electroplating bath according to claim 1 wherein R 3 and R 4 are independently selected from the group consisting of ethylene, propylene, —(CH 2 ) 2 —O—(CH 2 ) 2 —, and —(CH 2 ) 2 —O—(CH 2 ) 2 —O—(CH 2 ) 2 —.

4. The aqueous acidic copper electroplating bath according to claim 1 wherein the ureylene polymers according to Formulae (I), (II) and (III) do not have organically bound halogen.

5. The aqueous acidic copper electroplating bath according to claim 1 wherein the terminal amino groups in the ureylene polymer according to Formulae (I), (II) and (III) are quaternised with a residue selected from H, alkyl, allyl and benzyl.

6. The aqueous acidic copper electroplating bath according to claim 1 wherein the ureylene polymer of Formulae (I), (II) and (III) has a weight average molecular mass Mw in the range of 1000 to 20000 Da.

7. The aqueous acidic copper electroplating bath according to claim 1 wherein the concentration of copper ions ranges from 4 to 90 g/l.

8. The aqueous acidic copper electroplating bath according to claim 1 wherein the acid is selected from sulfuric acid, fluoro boric acid, phosphoric acid and methane sulfonic acid.

9. The aqueous acidic copper electroplating bath according to claim 1 wherein the aqueous acidic copper electroplating bath further comprises halide ions.

10. The aqueous acidic copper electroplating bath according to claim 9 wherein concentration of halide ions ranges from 20 mg/l to 200 mg/l.

11. The aqueous acidic copper electroplating bath according to claim 1 wherein the aqueous acidic copper electroplating bath further comprises an accelerator-brightener additive selected from organic thiol-, sulfide-, disulfide- and polysulfide-compounds.

12. A method for deposition of copper onto a substrate comprising, in this order, the steps

a. providing a substrate and

b. contacting the substrate with an aqueous acidic copper electroplating bath according to claim 1 ,

c. applying an electrical current between the substrate and at least one anode,

and thereby depositing copper onto the substrate.

13. The method for deposition of copper onto a substrate according to claim 12 wherein the substrate is selected from printed circuit boards, IC substrates, semiconducting wafers and glass substrates.

14. The method for deposition of copper onto a substrate according to claim 12 wherein copper is deposited into recessed structures selected from trenches, blind micro vias, through silicon vias and through glass vias.

15. The aqueous acidic copper electroplating bath according to claim 2 wherein R 3 and R 4 are independently selected from the group consisting of ethylene, propylene, —(CH 2 ) 2 —O—(CH 2 ) 2 —, and —(CH 2 ) 2 —O—(CH 2 ) 2 —O—(CH 2 ) 2 —.

16. The method for deposition of copper onto a substrate according to claim 13 wherein copper is deposited into recessed structures selected from trenches, blind micro vias, through silicon vias and through glass vias.