Patent ID: 7794573

Claim:
A system for wet chemical processing of microfeature workpieces, the system comprising: a processing unit for conveying a first processing fluid to a microfeature workpiece; an electrode unit coupled to the processing unit, the electrode unit including an electrode and being configured for conveying a second processing fluid proximate to the electrode; a barrier between the processing unit and the electrode unit to inhibit selected matter from passing between the first and second processing fluids; a vessel in fluid communication with the processing unit, the vessel configured for containing the first processing fluid; a gas inlet positioned to flow gas over a surface of the first processing fluid in the vessel for vaporizing water in the first processing fluid; a vacuum source positioned to draw off the gas and vaporized water out of the vessel; a sensor for detecting a concentration of water in the first processing fluid; a water source for adding water to the first processing fluid; and a controller coupled to the sensor and the water source for controlling addition of water to the first processing fluid based on the detected concentration of water in the first processing fluid.