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.