Process method for achieving uniform stress free electro-polishing across a copper plated wafer
A method of electro-polishing a copper plated wafer. The method includes providing an opening which is at least as long as the copper plated wafer. The method includes dispensing an electrolyte through the opening such that the electrolyte contacts the copper plated wafer, and while dispensing the electrolyte through the opening, relative movement is effected between the opening and the copper plated wafer. The opening can have a uniform width, be convex, concave, or take any other shape depending on the application. The copper plated wafer can be moved linearly across the opening and can also be rotated. The electrolyte can be delivered to a process tank having a containment device thereon which provides the opening. As such, the opening functions an overflow weir.
1 . A method of electro-polishing a copper plated wafer having a longitudinal diameter dimension, said method comprising: providing an opening having a longitudinal dimension, said longitudinal dimension of said opening being at least as long as the longitudinal diameter dimension of the copper plated wafer; dispensing an electrolyte through said opening such that the electrolyte contacts the copper plated wafer; while dispensing the electrolyte through said opening, effecting relative movement between the opening and the copper plated wafer such that the longitudinal diameter dimension of the copper plated wafer moves across the longitudinal dimension of the opening.
2 . A method as recited in claim 1 , wherein the opening has a uniform width.
3 . A method as recited in claim 1 , wherein the opening is convex.
4 . A method as recited in claim 1 , wherein the opening is concave.
5 . A method as recited in claim 1 , wherein the step of effecting relative movement between said opening and the copper plated wafer comprises linearly moving at least one of the copper plated wafer and the opening.
6 . A method as recited in claim 5 , further comprising rotating the copper plated wafer.
7 . A method as recited in claim 1 , further comprising delivering the electrolyte to a process tank, said tank having a containment device thereon which provides the opening.