Isn paddle-agitated deposition an unusual technique?
No. Vertical paddle agitation deposition was developed by IBM in the 1970’s for critical electroplating processes used in the thin film heads industry where fountain process cells could not deliver the required results. A paddle moving rapidly back and forth in front of the wafer surface creates much better fluid mixing than occurs in horizontal fountain cells, providing a variety of process advantages. Horizontal fountain cell plating has been used because, prior to Stratus, equipment vendors had not developed a cost-effective and reliable perimeter fluid seal and electrical contact suitable for vertical orientation. The Stratus ShearPlate electrodeposition process cell is an economical and reliable means of achieving a thin, uniform boundary layer.
