The present invention is directed to a method and apparatus for plating a
surface of a semiconductor workpiece (wafer, flat panel, magnetic films,
etc.) using a liquid conductor that makes contact with the outer surface
of the workpiece. The liquid conductor is stored in a reservoir and pump
through an inlet channel to the liquid chamber. The liquid conductor is
injected into a liquid chamber such that the liquid conductor makes
contact with the outer surface of the workpiece. An inflatable tube is
also provided to prevent the liquid conductor from reaching the back face
of the workpiece. A plating solution can be applied to the front face of
the workpiece where a retaining ring/seal further prevents the plating
solution and the liquid conductor from making contact with each other. In
an alternative embodiment, electrical contacts may be formed using an
inflatable tube that has either been coated with a conductive material or
contains a conductive object. The inflatable tube further provides
uniform contact and pressure along the periphery of the workpiece, which
may not necessarily be perfectly flat, because the tube can conform
according to the shape of the periphery of the workpiece. Further, the
present invention can be used to dissolve/etch a metal layer from the
periphery of the workpiece.