| 摘要 |
PROBLEM TO BE SOLVED: To enlarge the effective plating range of a cathode and to prolong the time up to a short circuit of an auxiliary cathode and a cathode electrode by making the inside diameter of the cathode electrode for cathode equal to that of an auxiliary cathode for controlling plated film thickness distribution and making the inside diameter of an exposed conductive part of the auxiliary electrode larger than the inside diameter of the cathode. SOLUTION: The plating is performed by adhering a wafer with the cathode electrode 21 by a cylinder 23 to use as the cathode and impressing voltage between an anodes 24 by a DC power source 25 and simultaneously voltage is impressed to the auxiliary electrode 52 placed on the cathode electrode 21 through an insulating body 33 from DC power source 25' to uniformalize the plated film thickness. In the plating device, the adhesion of the cathode 10 is secured by making the inside diameter of the auxiliary electrode 52 equal to that of the cathode electrode 21. Further, an insulating layer 53 is provided at least one the inner surface of the auxiliary electrode 52, the inside diameter of the exposed conductive part of the auxiliary electrode 52 is increased and the difference from that of the cathode electrode 21 is controlled to 2-16 mm, preferably 2-12 mm. As a result, product yield is improved with the uniform plating surface enlarged and the period up to the generation of short circuit caused by the deposit on the auxiliary cathode 52 is prolonged.
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