Cleaning electroplating substrate holders using reverse current deplating

摘要

Provided are cleaning methods and systems to remove unintended metallic deposits from electroplating apparatuses using reverse current deplating techniques. Such cleaning involves positioning a cleaning (deplating) disk in an electroplating cup similar to a regular processed substrate. The front surface of the cleaning disk includes a corrosion resistant conductive material to form electrical connections to deposits on the cup's surfaces. The disk is sealed in the cup and submerged into a plating solution. A reverse current is then applied to the front conductive surface of the disk to initiate deplating of the deposits. Sealing compression in the cup may change during cleaning to cause different deformation of the lip seal and to form new electrical connections to the deposits. The proposed cleaning may be applied to remove deposits formed during electroplating of alloys, in particular, tin-silver alloys widely used for semiconductor and wafer level packaging.

主权项

1. A method of mitigating an electroplating deposit on a substrate holder that is configured to hold a wafer substrate in an electroplating cell while applying a cathodic current to electroplate metal on the substrate, the method comprising:
when the electroplating cell is not being used for electroplating metal on a substrate, providing a deplating disk in the substrate holder such that the deplating disk makes electrical contact with a plurality of electrical contacts in the substrate holder; immersing the deplating disk and substrate holder into an electroplating solution within the electroplating cell; and applying an anodic potential to the deplating disk under conditions sufficient to remove, at least partially, the electroplating deposit from the substrate holder, wherein the deplating disk has a size and a shape matching those of a standard semiconductor wafer.