Unbalanced Magnetic Option (PP)  

Unbalanced magnetic field. Conventional 2 pole magnetic array. Increases plasma reactivity. Aids compound formation. Densify coatings. Suitable for all ion assisted process Specify optimum plasma release to the substrate. Substrate temperature will be increased. Possible to combine with all other options except for SW option.

The unbalanced magnetic array changes the shape of the magnetic field to allow release of some of the plasma electron towards the substrate. This release can be a 'maximum' or can be tuned to a certain level through the magnetic design. Since the field shape changes, so does the position of the outer edge of the race-track, hence the outer diameter of an unbalanced (PP type) magnetic array is much larger than a balanced (SW type) magnetic array in order to ensure sputtering to the outer edge of the target. Gencoa circular magnetrons are hence 'over-sized' in order to accept any type of magnetic array without compromising the process efficiency, target use and uniformity.

Please also refer to  FE modelling and Balance & Unbalance.