Patent ID: 9045841
Filing Date: 2015-06-02
Classification: C25D

Abstract:
1. A method of controlling the composition of an electrolyte bath for electroplating a metal onto a wafer, the method comprising: providing one or more wafers sequentially to a catholyte portion of a plating cell having a separate anode chamber configured for holding an anode and maintaining an anolyte in ionic communication with the catholyte via a cation exchange membrane on the separate anode chamber; recirculating the anolyte; providing a diluent to the recirculating anolyte and providing a make-up solution to the recirculating anolyte, while separately controlling delivery of the diluent and of the make up solution to the recirculating anolyte, wherein the dosing parameters for the diluent and the make up solution are selected such as to minimize precipitation-induced passivation of the anode.