Electrolytic copper plating solution and method of electrolytic copper plating
View Patent ↗An electrolytic copper plating solution is provided which has an excellent via filling ability without using formaldehyde, which is harmful to the environment. An electrolytic copper plating solution which contains compounds which have an —X—S—Y— structure wherein X and Y are individually atoms selected from a group comprising hydrogen, carbon, sulfur, nitrogen, and oxygen atoms and X and Y can be the same only when they are carbon atoms and specific nitrogen-containing compounds. Good filled vias can be made without causing a worsening of the exterior appearance of the plating by using this electrolytic copper plating solution.
1. An electrolytic copper plating solution comprising copper sulfate, copper cyanide or copper pyrophosphate; a compound shown by general formula (1):
wherein R 1 to R 6 are, independent of each other, and are alkyl groups with carbon numbers of 1 to 4 which are optionally substituted with hydrogen atoms or functional groups; and compounds selected from the group consisting of:
(1) M-SO 3 —(CH 2 ) a —S—(CH 2 ) b —SO 3 -M;
(2) M-SO 3 —(CH 2 ) a —O—CH 2 —S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(3) M-SO 3 —(CH 2 ) a —S—S—(CH 2 ) b —SO 3 -M;
(4) M-SO 3 —(CH 2 ) a —O—CH 2 —S—S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(5) M-SO 3 —(CH 2 ) a —S—C(═S)—S—(CH 2 ) b —SO 3 -M; and
(6) M-SO 3 —(CH 2 ) a —O—CH 2 —S—C(═S)—S—CH 2 —O—(CH 2 ) b —SO 3 -M,
wherein a and b in compounds (1)-(6) are integers from 3 to 8, M is hydrogen or an alkali metal element.
2. An electrolytic copper plating solution comprising copper sulfate, copper cyanide or copper pyrophosphate; a compound shown by general formula (2):
wherein R 1 , R 3 and R 5 are, independent of each other, and are alkyl groups with carbon atom numbers of 1 to 4 which are optionally substituted with hydrogen atoms or functional groups;
and compounds selected from the group consisting of:
(1) M-SO 3 —(CH 2 ) a —S—(CH 2 ) b —SO 3 -M;
(2) M-SO 3 —(CH 2 ) a —O—CH 2 —S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(3) M-SO 3 —(CH 2 ) a —S—S—(CH 2 ) b —SO 3 -M;
(4) M-SO 3 —(CH 2 ) a —O—CH 2 —S—S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(5) M-SO 3 —(CH 2 ) a —S—C(═S)—S—(CH 2 ) b —SO 3 -M; and
(6) M-SO 3 —(CH 2 ) a —O—CH 2 —S—C(═S)—S—CH 2 —O—(CH 2 ) b —SO 3 -M,
wherein a and b in compounds (1)-(6) are integers from 3 to 8, M is hydrogen or an alkali metal element.
3. An electrolytic copper plating solution comprising copper sulfate, copper cyanide or copper pyrophosphate; a compound shown by general formula (3):
wherein R 2 , R 4 and R 6 are, independent of each other, and are hydrogen atoms or alkyl groups with carbon numbers of 1 to 4; and compounds selected from the group consisting of:
(1) M-SO 3 —(CH 2 ) a —S—(CH 2 ) b —SO 3 -M;
(2) M-SO 3 —(CH 2 ) a —O—CH 2 —S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(3) M-SO 3 —(CH 2 ) a —S—S—(CH 2 ) b —SO 3 -M;
(4) M-SO 3 —(CH 2 ) a —O—CH 2 —S—S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(5) M-SO 3 —(CH 2 ) a —S—C(═S)—S—(CH 2 ) b —SO 3 -M; and
(6) M-SO 3 —(CH 2 ) a —O—CH 2 —S—C(═S)—S—CH 2 —O—(CH 2 ) b —SO 3 -M,
wherein a and b in compounds (1)-(6) are integers from 3 to 8, M is hydrogen or an alkali metal element.
4. A method of copper electroplating comprising:
a) providing a substrate;
b) providing a copper electroplating solution comprising copper sulfate, copper cyanide or copper pyrophosphate; a compound shown by general formula (1):
wherein R 1 to R 6 are, independent of each other, and are alkyl groups with carbon numbers of 1 to 4 which are optionally substituted with hydrogen atoms or functional groups; and compounds selected from the group consisting of:
(1) M-SO 3 —(CH 2 ) a —S—(CH 2 ) b —SO 3 -M;
(2) M-SO 3 —(CH 2 ) a —O—CH 2 —S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(3) M-SO 3 —(CH 2 ) a —S—S—(CH 2 ) b —SO 3 -M;
(4) M-SO 3 —(CH 2 ) a —O—CH 2 —S—S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(5) M-SO 3 —(CH 2 ) a —S—C(═S)—S—(CH 2 ) b —SO 3 -M; and
(6) M-SO 3 —(CH 2 ) a —O—CH 2 —S—C(═S)—S—CH 2 —O—(CH 2 ) b —SO 3 -M,
wherein a and b in compounds (1)-(6) are integers from 3 to 8, M is hydrogen or an alkali metal element;
c) immersing the substrate in the copper electroplating solution; and
d) electroplating copper on the substrate.
5. A method of copper electroplating comprising:
a) providing a substrate;
b) providing a copper electroplating solution comprising copper sulfate, copper cyanide or copper pyrophosphate; a compound shown by general formula (2):
wherein R 1 , R 3 and R 5 are, independent of each other, and are alkyl groups with carbon atom numbers of 1 to 4 which are optionally substituted with hydrogen atoms or functional groups; and compounds selected from the group consisting of:
(1) M-SO 3 —(CH 2 ) a —S—(CH 2 ) b —SO 3 -M;
(2) M-SO 3 —(CH 2 ) a —O—CH 2 —S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(3) M-SO 3 —(CH 2 ) a —S—S—(CH 2 ) b —SO 3 -M;
(4) M-SO 3 —(CH 2 ) a —O—CH 2 —S—S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(5) M-SO 3 —(CH 2 ) a —S—C(═S)—S—(CH 2 ) b —SO 3 -M; and
(6) M-SO 3 —(CH 2 ) a —O—CH 2 —S—C(═S)—S—CH 2 —O—(CH 2 ) b —SO 3 -M,
wherein a and b in compounds (1)-(6) are integers from 3 to 8, M is hydrogen or an alkali metal element;
c) immersing the substrate in the copper electroplating solution; and
d) electroplating copper on the substrate.
6. A method of copper electroplating comprising:
a) providing a substrate;
b) providing a copper electroplating solution copper sulfate, copper cyanide or copper pyrophosphate; a compound shown by general formula (3):
wherein R 2 , R 4 and R 6 are, independent of each other, and are hydrogen atoms or alkyl groups with carbon numbers of 1 to 4; and compounds selected from the group consisting of:
(1) M-SO 3 —(CH 2 ) a —S—(CH 2 ) b —SO 3 -M;
(2) M-SO 3 —(CH 2 ) a —O—CH 2 —S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(3) M-SO 3 —(CH 2 ) a —S—S—(CH 2 ) b —SO 3 -M;
(4) M-SO 3 —(CH 2 ) a —O—CH 2 —S—S—CH 2 —O—(CH 2 ) b —SO 3 -M;
(5) M-SO 3 —(CH 2 ) a —S—C(═S)—S—(CH 2 ) b —SO 3 -M; and
(6) M-SO 3 —(CH 2 ) a —O—CH 2 —S—C(═S)—S—CH 2 —O—(CH 2 ) b —SO 3 -M,
wherein a and b in compounds (1)-(6) are integers from 3 to 8, M is hydrogen or an alkali metal element;
c) immersing the substrate in the copper electroplating solution; and
d) electroplating copper on the substrate.