A cathode current control system employing a current thief for use in
electroplating a wafer is set forth. The current thief comprises a
plurality of conductive segments disposed to substantially surround a
peripheral region of the wafer. A first plurality of resistance devices
are used, each associated with a respective one of the plurality of
conductive segments. The resistance devices are used to regulate current
through the respective conductive finger during electroplating of the
wafer. Various constructions are used for the current thief and further
conductive elements, such as fingers, may also be employed in the system.
As with the conductive segments, current through the fingers may also be
individually controlled. In accordance with one embodiment of the overall
system, selection of the resistance of each respective resistance devices
is automatically controlled in accordance with predetermined programming.