Patent ID: 7147827

Claim:
A chemical control system for controlling the chemistry of a chemical solution having predetermined chemical constituents in a plating system, the chemical control system comprising: a mix containter for containing a plating solution; a hold container for containing a plating solution delivered from said mix container; a precision delivery arrangement for delivering a predetermined quantum of a predetermined constituent of the plating solution to said mix container, said hold container, or both; a transfer pump for urging the plating solution to be transferred from said mix container to said hold container; a source of deionized water in communication with said mix container; and a nitrogen gas source in communication with said source of deionized water for providing to said mix container a flow of nitrogen source gas to which has been added deionized water to form humidified nitrogen gas, the humidified nitrogen gas being humidified to a predetermined relative humidity with respect to the temperature of the plating solution in said mix container.