Granted Patent B2

US 12,612,709 · App. 18/159,343 · Granted Apr 28, 2026

Inventors: Anne Hickey (Cambridge, MA); Kristen M. Griffin (Boylston, MA)

Assignee: DuPont Electronic Materials International, LLC

C25D3/54C23F15/00

Abstract

Claims (9)

1 . A method of electroplating bismuth comprising: providing a substrate comprising silver, silver alloy, gold or gold alloy; providing a bismuth electroplating bath comprising (i) a source of bismuth ions, and (ii) an acid, a salt of an acid or combinations thereof, wherein the bismuth electroplating bath has a pH of less than 7; contacting the substrate with the bismuth electroplating bath; applying a current to the bismuth electroplating bath and substrate; and electroplating bismuth on the silver, silver alloy, gold or gold alloy of the substrate to a thickness of greater than 0 to equal to or less than 20 nm.

2 . The method of claim 1 , wherein the thickness ranges from greater than 1 nm to 10 nm.

3 . The method of claim 2 , wherein the thickness ranges from greater than 1 nm to 7 nm.

4 . The method of claim 1 , wherein a current density for electroplating the bismuth ranges from 0.1 ASD and higher.

5 . The method of claim 4 , wherein the current density for electroplating the bismuth ranges from 0.1-5 ASD.

6 . The method of claim 1 , wherein the bismuth electroplating bath has a pH of from 0 to 6.

7 . The method of claim 6 , wherein the bismuth electroplating bath has a pH of from 0 to 2.

8 . The method of claim 1 , wherein the acid, the salt of an acid or the combinations thereof comprises an organic acid chosen from alkane sulfonic acids, alkanol sulfonic acids, or aromatic sulfonic acids, a salt of the organic acid, or a combination thereof.

9 . The method of claim 8 , wherein the acid comprises an organic acid chosen from alkane sulfonic acids.

Assignments (3)

Continuity (2)

References Cited (33)