CPC C25D 17/001 (2013.01) [C25D 3/38 (2013.01); C25D 17/002 (2013.01); C25D 17/10 (2013.01); C25D 21/14 (2013.01); C25D 21/18 (2013.01); H01L 21/2885 (2013.01)] | 18 Claims |
1. A method of electroplating a metal onto a substrate during fabrication of a device, the method comprising:
(a) providing an electroplating solution to an electroplating system comprising:
(i) an electroplating cell comprising an anode chamber and a cathode chamber and configured to hold the substrate in the cathode chamber while electroplating the metal onto the substrate,
(ii) an electroplating solution reservoir configured to hold a portion of the electroplating solution while electroplating the metal onto the substrate,
(iii) a recirculation system for delivering the electroplating solution between the electroplating cell and the electroplating solution reservoir,
(iv) a make-up solution inlet for providing make-up solution to the electroplating system,
(v) a secondary electroplating solution inlet for providing a secondary electroplating solution to the electroplating system, and
(vi) an outlet for removing the electroplating solution from the electroplating system,
wherein the electroplating solution comprises multiple components for electroplating the metal onto the substrate;
(b) electroplating the metal onto the substrate while the substrate is held in the cathode chamber;
(c) supplying the make-up solution to the electroplating system via the make-up solution inlet, wherein the make-up solution comprises some or all of the multiple components for electroplating the metal onto the substrate, wherein supplying the make-up solution to the electroplating system changes a composition of the electroplating solution so that at least one of the multiple components in the electroplating solution moves closer to its target concentration;
(d) supplying the secondary electroplating solution to the electroplating system via the secondary electroplating solution inlet, wherein the secondary electroplating solution comprises some or all of the multiple components, and wherein at least one of the following conditions (1) and (2) is satisfied:
(1) the secondary electroplating solution comprises at least one of the multiple components at a secondary concentration that is significantly higher than its target concentration,
(2) the secondary electroplating solution comprises at least one of the multiple components at a secondary concentration that is significantly lower than its target concentration; and
(e) removing the electroplating solution from the electroplating system via the outlet, wherein operations (c) and (e) are part of a bleed-and-feed process,
wherein the metal is copper, and wherein the secondary electroplating solution comprises copper ions at a secondary concentration that is significantly higher than a target concentration for copper ion in the electroplating solution.
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