Non-reagent chloride analysis in acid copper plating baths

1 . A method for non reagent chloride analysis in an acid copper plating bath, comprising:

adding a blend solution including VMS (Virgin Makeup Solution) into an acid copper plating bath including Cl, and generating an anodic dissolution of an Ag electrode into the plating bath, thereby generating an Ag + -containing solution in an Ag + -containing solution generation cell separate from a titration cell;

transferring, via a pump, adding the generated Ag + -containing solution as a silver titrant from the Ag + -containing solution generation cell into an electrolyte including an analysis sample in the titration cell; and

analyzing chloride concentration in the sample, via measuring at least one working electrode (WE) potential in a predetermined potential range.

2 . The method of claim 1 , wherein the VMS includes at least CuSO 4 , H 2 SO 4 , and/or HCl.

3 . The method of claim 1 , wherein the blend solution further comprises DIW (Deionized Water).

4 . The method of claim 1 , wherein concentration of VMS in the blend solution is less than 15% by volume.

5 . The method of claim 1 , wherein the WE is an Ag (ISE).

6 . An electrochemical system for non reagent chloride analysis in acid Cu plating bath, comprising:

an Ag + -containing solution generation unit, comprising:

a potentiostat;

an Ag + -containing solution generation cell including an acid copper plating bath;

an Ag anode and a cathode connected to the potentiostat; and

a VMS vessel and a DIW vessel, configured to deliver a blend solution of VMS and DIW into the Ag + -containing solution generation cell,

a titration unit, comprising:

a titrator,

a titration cell containing an Ag ISE (ion selective electrode) and a stirrer, connecting the titrator and the titration cell, and

a sample vessel and a DIW vessel, configured to deliver a sample solution into the titration cell,

and

a pump delivering the Ag-containing solution from the Ag + -containing solution generation cell to the titration cell.

7 . The system of claim 6 , wherein the Ag anode is a silver metal wire or rod.

8 . The system of claim 6 , wherein the cathode is a platinum wire or stainless-steel rod.

9 . The system of claim 6 , wherein the system further comprises a computing device having a memory element with a stored algorithm operative for

delivering VMS at a predetermined concentration into the Ag + -containing solution generation cell to produce the Ag + -containing solution,

delivering the Ag + -containing solution at a constant predetermined flow rate from the Ag + -containing generation cell into the titration cell,

scanning potential of the Ag ISE electrode relative to a reference electrode at a predetermined positive potential limit at a predetermined potential scan rate, and

measuring chloride concentration in the sample.

10 . The system of claim 6 , wherein the titration cell is connected to a drain downstream thereof.