Abstract:
Plating accelerator is applied selectively to a substantially-unfilled wide (e.g., low-aspect-ratio feature cavity. Then, plating of metal is conducted to fill the wide feature cavity and to form an embossed structure in which the height of a wide-feature metal protrusion over the metal-filled wide-feature cavity is higher than the height of metal over field regions. Most of the overburden metal is removed using non-contact techniques, such as chemical wet etching. Metal above the wide feature cavity protects the metal-filled wide-feature interconnect against dishing, and improved planarization techniques avoid erosion of the metal interconnect and dielectric insulating layer. In some embodiments, plating of metal onto a substrate is conducted to fill narrow (e.g., high-aspect-ratio feature cavities) in the dielectric layer before selective application of plating accelerator and filling of the wide feature cavity.
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.