Abstract: An apparatus for engaging a work piece during plating facilitates electrolyte flow during a plating operation. The apparatus helps to control the plating solution fluid dynamics and electric field shape to keep the wafer's local plating environment uniform and bubble free. The apparatus holding the work piece in a manner that facilitates electrolyte circulation patterns in which the electrolyte flows from the center of the work piece plating surface, outward toward the edge of the edge of the work piece. The apparatus holds the work piece near the work piece edges and provides a flow path for electrolyte to flow outward away from the edges of the work piece plating surface. That flow path has a “snorkel” shape in which the outlet is higher than the inlet. In addition, the flow path may have a slot shape that spans much or all of the circumference of holding apparatus. It may be made from a material that resists deformation and corrosion such as certain ceramics.

Abstract: A treating head having a treating surface and a substrate treatment surface define a thin fluid gap that is filled with reactant liquid to form a thin liquid layer on the substrate for conducting a liquid chemical reaction treatment or other liquid treatment of the substrate. The thin liquid layer has a volume in a range of about from 50 ml to 500 ml. Preferably, the chemical composition, temperature, and other properties of liquid in the thin liquid layer are dynamically variable.

Abstract: A passive mechanism for centering a wafer on a chuck and with respect to a backside exclusion gas ring includes a plurality of wheels that are rotatably mounted in a circular pattern at the top surface of a chuck. The axis of rotation of each wheel is parallel to the top surface of the chuck and perpendicular to a radius extending outward from the centerpoint of the chuck surface. When a wafer is placed on the chuck, its edge contacts the wheels and, by its own weight, the wafer moves toward the center of the chuck, thereby centering itself. The wafer either slides on the wheels or, if the frictional force between the wafer and one or more of the wheels is great enough, the wafer causes the wheel to turn. The wheels may be mounted on the chuck, a carrier ring or a wafer transfer arm for moving wafers between processing stations. In one embodiment the alignment wheels are mounted on a carrier ring, and a second alignment mechanism aligns the carrier ring to the chuck.