Magnetron cathode and method for sputter coating

Claim 1

Sputter coating apparatus comprising: (a) means for supporting a generally circular substrate at a coating position; (b) target means comprising a coating material for coating the substrate, said target means fixed with respect to said substrate and having a concave sputter surface of coating material facing the generally circular substrate that includes a generally circular flat inner portion bounded around an outer periphery by a wall portion inclined toward the substrate; (c) means for providing ions in a region between the target and the substrate; (d) accelerating means for accelerating ions in the region between the target and the substrate causing the ions to impact the target and eject coating material from said sputtering surface to coat the substrate; and (e) field generating means for creating a magnetic field in the region between the target and the substrate to localize ionization of gas molecules by electrons in said region, said field generating means including two or more current carrying coils symmetric about an axis that intersects the substrate and the target, means for individually controlling both the polarity and magnitude of current flow through each of said current carrying coils and further including a center ferromagnetic pole piece coaxial with a centerline passing through the circular flat inner portion of said target and two or more annular ferromagnetic pole pieces that are spaced from each other by said two or more current carrying coils; wherein some of said pole pieces are shared by adjacent coils so that controlled energization of the coils of specified polarity and magnitude both increases and decreases magnetization of the shared pole pieces to control target erosion of the vicinity of said shared pole pieces; said controlled energization simultaneously producing and scanning distinct target erosion rings on the inner and wall portions of said target when adjacent coils are energized with an opposite polarity and a single widened ring extending radially outward toward the inclined region of said target if said two or more coils are energized with the same polarity or only one of said coils is energized.

Claim 13

A method for sputter coating a generally circular, planar substrate with a target material comprising the steps of: (a) positioning a concave target having a generally planar inner base and radially outer inclined walls in proximity to the substrate so that said substrate is generally parallel to the generally planar base of the target; (b) positioning a plurality of electro-magnetic pole pieces in symmetric relation to an axis that intersects both the target and the substrate; (c) positioning two or more electro-magnetic coils concentrically around the axis to modify the magnetic field in a region between the substrate and the target; (d) establishing an electric field in a region between the substrate and the target to cause ions in said region to bombard said target; and (e) adjusting the polarity and magnitude of current in said two or more electro-magnetic coils to cause said ions to bombard said target in multiple concentrated circular regions spaced from each other about said axis, said coil energization causing the concentrated regions to move radially inward and outward along the base and inclined walls of said target to erode said target not only along the base and inclined walls but in a transition region between the base and the inclined walls.

Claim 14

A method for sputter coating a generally circular, planar substrate with a target material comprising the steps of: (a) positioning a concave target having a generally planar inner base and radially outer inclined walls in proximity to the substrate so that said substrate is generally parallel to the generally planar base of the target; (b) positioning a plurality of electro-magnetic pole pieces in symmetric relation to an axis that intersects both the target and the substrate; (c) positioning two or more electro-magnetic coils concentrically around the axis to modify the magnetic field in a region between the substrate and the target; (d) establishing an electric field in a region between the substrate and the target to cause ions in said region to bombard said target; and (e) adjusting the polarity and magnitude of current in said two or more electro-magnetic coils to cause said ions to bombard said target in multiple concentrated circular regions spaced from each other about said axis, said coil energization causing the concentrated regions to move radially inward and outward along the base and inclined walls of said target to erode said target not only along the base and inclined walls but in a transition region between the base and the inclined walls.