Abstract: A semiconductor workpiece holder used in electroplating systems for plating metal layers onto a semiconductor workpieces, and is of particular advantage in connection with plating copper onto semiconductor materials. The workpiece holder includes electrode assemblies which have a contact part which connects to a distal end of an electrode shaft and bears against the workpiece and conducts current therebetween. The contact part is preferably made from a corrosion resistant material, such as platinum. The electrode assembly also preferably includes a dielectric layer which covers the distal end of the electrode shaft and seals against the contact part to prevent plating liquid from corroding the joint between these parts.