Methods of and apparatus for electroplating preselected surface regions of electrical articles

Abstract

An article, such as a semiconductor wafer (31), is selectively electrolytically plated to form metal deposits, such as contacts (26), adjacent to anodes of diode regions within such wafer by mounting the wafer in a plating chamber (36) opposite first and second electrodes (61 and 62), filling the chamber (36) with a metal plating electrolyte (49) and applying alternatingly plating pulses between the wafer (31) and the first electrode (61) and deplating pulses between the wafer (31) and the second electrode (62). The plating pulses are current controlled yielding a predetermined total plating current. The deplating pulses are voltage controlled yielding a deplating current which tends to subside in the course of the plating operation. The electrolyte in the chamber is agitated by streams of electrolyte pumped at a comparatively high rate toward the wafer (31) to break down surface layers of electrolyte adjacent to the wafer.

Dependencies are inferred from the claim text.