Patent ID: 8852412

Claim:
A magnetron source comprising a target with a sputtering surface and a back surface, along the back surface a magnet arrangement of permanent magnets, said magnet arrangement comprising an outer magnet arrangement arranged along a predominant part of an outer geometric frame shaped or loop shaped locus and having one type magnetic pole facing said back surface, and an inner magnet arrangement arranged along a predominant part of an inner geometric frame shaped or loop shaped locus within said outer geometric frame shaped or loop shaped locus and having the other type of magnetic pole facing said back surface, said outer and inner geometric loci defining an interspace, said outer and inner magnet arrangements generating along said sputtering surface a tunnel shaped magnetron magnetic field along a loop as defined by said inner and outer geometric loci, said magnet arrangement being drivingly movable along and relative to said back surface of said target, the magnetron source characterized by said magnet arrangement comprising at least one elongated permanent magnet arrangement, elongated centrally along an axis parallel to, along and distant from said back surface and aligned with said interspace, said elongated arrangement being controllably drivingly rotatable about said axis and comprising permanent magnet dipoles radially arranged along and relative to said axis, wherein said elongated arrangement is both cylindrical about said axis parallel to said back surface and rotatable around said axis such that the elongated arrangement is coaxial with said axis, and wherein said magnet arrangement further comprises a second elongated permanent magnet arrangement rotatable about a second axis parallel to, along and distant from said back surface and aligned with said interspace, said elongated arrangement and said second elongated arrangement being respectively rotatable about said axis parallel to said back surface and said second axis parallel to said back surface with different angular velocities, said target being circular and having a center, said outer magnet arrangement having a spoke extension that extends from the outer magnet arrangement towards the center of said circular target in a direction generally parallel to the back surface of the target, said outer and inner magnet arrangements thereby generating said magnetic field also across and bridging over said center.