Aqueous copper plating baths and a method for deposition of copper or copper alloy onto a substrate

Patent metadata

Field	Value
Publication number	US-2018223442-A1
Application number	US-201615748332-A
Country	US
Kind code	A1
Filing date	Aug 30, 2016
Priority date	Aug 31, 2015
Publication date	Aug 9, 2018
Grant date	—

Abstract

The present invention relates to bisurea derivatives and their use in aqueous plating baths for copper and copper alloy deposition in the manufacture of printed circuit boards, IC substrates, semiconducting and glass devices for electronic applications. The plating bath according to the present invention comprises at least one source of copper ions and a bisurea derivative. The plating bath is particularly useful for filling recessed structures with copper and build-up of pillar bump structures.

First claim

1 . An aqueous copper plating bath for electrolytic copper or copper alloy deposition comprising at least one source of copper ions and at least one acid characterised in that the bath comprises at least one bisurea derivative comprising a bisurea building block according to formula (I)

wherein A represents a unit derived from a diurea compound of the following formula (A1)

wherein
X 1 and X 2 are divalent residues independently from each other selected from the following group consisting of

wherein R 1 and R 2 are monovalent residues each selected independently from the group consisting of hydrogen, alkyl and polyoxyalkylene;
Y is selected from CH 2 , O and S;
c is an integer ranging from 1 to 6; c′ is an integer ranging from 1 to 6;
b is an integer ranging from 1 to 5;
b′ is an integer ranging from 1 to 5;
Z is a divalent bridging moiety which is selected from the group consisting of alkylene, arylene and alkylene oxide compound whereby said alkylene oxide compound is represented by the following formula
—(CH 2 ) d —[CH(R 3 )—CH 2 —O] e —(CH 2 ) f —(CH(CH 3 )) f′ —,

wherein d is an integer ranging from 0 to 3;
e is an integer ranging from 1 to 100; and
f is an integer ranging from 1 to 3;
f′ is 0 or 1;
each R 3 is independently from each other selected from the group consisting of alkyl, aryl and hydrogen;
a is an integer and ranges from 1 to 100; and
D is a divalent residue and is selected from the group consisting of
—CH 2 —CH(OH)—CH 2 —,
—CH 2 —CH(SH)—CH 2 —, —(CH 2 ) g —[CH(R 4 )—CH 2 —O] h —(CH 2 ) i — and
—CH 2 —CH(OH)—(CH 2 ) j —[CH(R 5 )—CH 2 —O] k —(CH 2 ) l —CH(OH)—CH 2 —
wherein g is an integer ranging from 0 to 4;
h is an integer ranging from 1 to 100;
i is an integer ranging from 1 to 4;
each R 4 is independently from each other selected from the group consisting of alkyl, aryl and hydrogen;
j is an integer ranging from 1 to 4;
k is an integer ranging from 1 to 100;
l is an integer ranging from 1 to 4;
each R 5 is independently from each other selected from the group consisting of alkyl, aryl and hydrogen
and if a is 2 or greater each A and each D are selected independently from each other
and wherein the aqueous copper plating bath is free of intentionally added zinc ions.

2 . The aqueous copper plating bath according to claim 1 characterised in that the mass ratio of further reducible metal ions to copper ions ranges from 1/1 to 0/1.

3 . The aqueous copper plating bath according to claim 1 characterised in that the further reducible metal ions are selected from the group consisting of gold ions, tin ions, silver ions, and palladium ions.

4 . The aqueous copper plating bath according to claim 1 aqueous characterised in that the aqueous copper plating bath according to the invention is free of further reducible metal ions.

5 . The aqueous copper plating bath according to claim 1 characterised in that X 1 and X 2 are selected to be the same.

6 . The aqueous copper plating bath according to claim 1 characterised in that b and b′ are the same and range from 1 to 2.

7 . The aqueous copper plating bath according to claim 1 characterised in that D is selected from the group consisting of
—CH 2 —CH(OH)—CH 2 —,
—(CH 2 ) g —[CH(R 4 )—CH 2 —O] h —(CH 2 ) i — and
—CH 2 —CH(OH)—(CH 2 ) j —[CH(R 5 )—CH 2 —O] k ——(CH 2 ) l —CH(OH)—CH 2 —.

8 . The aqueous copper plating bath according to claim 7 characterised in that D is —(CH 2 ) g —[CH(R 4 )—CH 2 —O] h —(CH 2 ) i — and g is 0 and i is an integer ranging from 1 to 3.

9 . The aqueous copper plating bath according to claim 1 characterised in that the alkylene, arylene or alkylene oxide compound forming Z are free of nitrogen atoms.

10 . The aqueous copper plating bath according to claim 1 characterised in that each Z is selected to be an alkylene oxide compound represented by the formula
—(CH 2 ) d —[CH(R 3 )—CH 2 —O] e —(CH 2 ) f —(CH(CH 3 )) f′ — and

d is 0 and e is an integer ranging from 1 to 10 and f′ is 0.

11 . The aqueous copper plating bath according to claim 1 characterised in that the at least one bisurea derivative contains one or two terminating groups and is represented by the following formulae (IIa) to (IIc)

wherein the first terminating group (TG1) bound to a unit derived from diurea compound in the bisurea building block according to formula (I) is selected from the group consisting of E-G 1 -, R 6 -G 2 -,

wherein G 1 , G 2 and G 3 are divalent residues represented by the following formula —(CH 2 ) m —[CH(R 7 )—CH 2 —O] n —(CH 2 ) o — wherein m is an integer ranging from 0 to 3; n is an integer ranging from 1 to 100; o is an integer ranging from 1 to 3; each R 7 is independently from each other selected from the group consisting of alkyl, aryl and hydrogen;
E is a monovalent residue and is selected from triflate, nonaflate, alkylsulphonates, arylsulphonates and halogenides; and
R 6 is a monovalent residue selected from the group consisting of C 1 - to C 6 -alkyl, C 1 - to C 8 -alkenyl, aralkyl, aryl; and
the second terminating group (TG2) bound to divalent residue D in the bisurea building block according to formula (I) is selected from the group consisting of hydroxyl group (—OH), diurea compound A, monovalent residue E, C 1 - to C 8 -alkyl, aralkyl, aryl,

wherein G 4 is a divalent residue represented by the following formula —(CH 2 ) m —[CH(R 8 )—CH 2 —O] n —(CH 2 ) o — wherein m is an integer ranging from 0 to 3; n is an integer ranging from 1 to 100; o is an integer ranging from 1 to 3; each R 8 is independently from each other selected from the group consisting of alkyl, aryl and hydrogen;
E is a monovalent residue and is selected from triflate, nonaflate, alkylsulphonates, arylsulphonates and halogenides; and A is a diurea compound according to formula (A1).

12 . The aqueous copper plating bath according to claim 1 characterised in that the at least one bisurea derivative has a weight average molecular mass Mw of 500 to 50000 Da.

13 . The aqueous copper plating bath according to claim 1 characterised in that the concentration of the at least one bisurea derivative in the aqueous copper plating bath ranges from 0.1 mg/l to 1000 mg/l.

14 . A method for deposition of copper or copper alloy onto a substrate comprising the steps
(i) providing the substrate, (ii) contacting the substrate with the aqueous copper plating bath according to claim 1 , and (iii) applying an electrical current between the substrate and at least one anode,
and thereby depositing copper or copper alloy on at least a portion of a surface of the substrate.

15 . The method of claim 14 characterised in that the substrate is selected from the group consisting of printed

Assignees

• Atotech Deutschland Gmbh

Inventors

• Brunner Heiko
• Kohlmann Lars
• Witczak Agnieszka
• Mann Olivier

Classifications

• C25D7/123

  Semiconductors first coated with a seed layer or a conductive layer · CPC title

• C08G73/00

  Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00 {(polycarbodiimides prepared from isocyanates C08G18/025, C08G18/797)} · CPC title

• C25D3/38 Primary

  of copper · CPC title

• C25D3/58

  containing more than 50% by weight of copper · CPC title