Processes and systems for electrolytically processing a microfeature workpiece with a first processing fluid and a counter electrode are described. Microfeature workpieces are electrolytically processed using a first processing fluid, a counter electrode, a second processing fluid, and an anion permeable barrier layer. The anion permeable barrier layer separates the first processing fluid from the second processing fluid while allowing certain anionic species to transfer between the two fluids. Some of the described processes produce deposits over repeated plating cycles that exhibit resistivity values within desired ranges.