Rotating sputtering apparatus for selected erosion

A magnetron apparatus comprising:

• a vacuum chamber;
• a magnetron structure including an anode;
• a cathode having a front surface in said vacuum chamber and a back surface;
• magnetic means positioned behind said back surface for generating a magnetic field defining arcuate magnetic field lines intersecting said front surface and enclosing a closed loop path adjacent to said front surface, said closed loop path defining a centerline whereat said magnetic field strength is greatest;
• means for rotating said magnetic means about an axis passing through and normal to said surface;
• said magnetic means comprising an array of individual magnets positioned between two continuous, generally parallel closed loop pole pieces defining a centerline therebetween, said centerline generally corresponding to said centerline of said magnetic field, wherein the strength and positioning of the magnets in said array is such that the magnetic field strength of said closed loop path is substantially a constant value at all locations on said magnetic field centerline greater than a predetermined distance from said axis and is less than said constant value at all locations less than said predetermined distance from said axis.

A system for processing a wafer comprising:

• a vacuum chamber including an anode;
• a first magnetron apparatus within said vacuum chamber comprising:
• a first magnetron structure;
• a first cathode having a front surface in said vacuum chamber and a back surface;
• first closed loop magnetic means positioned behind said back surface of said first cathode for generating a magnetic field defining a closed loop magnetic field on said front surface of said first cathode in a region adjacent to said closed loop magnetic means;
• and
• means for rotating said first magnetic means about an axis which passes through and is normal to said first cathode front surface;
• and
• a second magnetron apparatus within said vacuum chamber comprising:
• a second magnetron structure;
• a second cathode having a front surface in said vacuum chamber and a back surface;
• second closed-loop magnetic means positioned behind said back surface of said second cathode for generating a magnetic field defining a closed loop magnetic field on said front surface of said second cathode in a region adjacent to said closed loop magnetic means;
• and
• means for rotating said second magnetic means about an axis which passes through and is normal to said second cathode front surface;
• wherein said first and second closed loop magnetic means each comprises first and second portions, all points on said first portion of each closed loop magnetic means being located a distance greater than or equal to a predetermined distance from the axis about which said magnetic means is rotated, and all points on said second portion of said closed loop magnetic means being located a distance less than said predetermined distance from the axis about which said magnetic means is rotated, wherein said first portion of each magnetic means produces a substantially constant magnetic field strength along the adjacent region of the adjacent cathode and wherein said second portion of the magnetic means produces a magnetic field of less intensity along the adjacent region of said cathode;
• wherein said first and second cathodes face each other, and wherein said first magnetron apparatus is primarily used for sputtering and said second magnetron apparatus is primarily used for etching.

A rotating magnet for use in a magnetron apparatus, comprising:

• first and second closed loop pole pieces defining a magnet centerline therebetween;
• an array of individual magnets positioned between said pole pieces;
• and
• means for rotating said magnet about an axis;
• wherein said closed loop comprises first and second regions, the first region being defined as the portion of the magnet along the points on the centerline greater than a predetermined distance from the axis of rotation, and the second region being defined as that portion of the magnet along the points on the centerline less than said predetermined distance from the axis of rotation, all of the magnets positioned in said first region being substantially equal in strength and substantially evenly spaced apart so as to produce a magnetic field which has a substantially constant intensity adjacent to said magnet centerline, and wherein at least some of the magnets positioned in said second region have a substantially lower strength than the magnets of said first region, such that the magnetic field intensity adjacent to the magnet centerline in said second region is substantially less than in said first region.