Methods and apparatus for sputtering with rotating magnet sputter sources

A magnetron sputtering apparatus comprising:

• a first magnetron sputtering source for forming a sputtered film on a first surface of a substrate, said first magnetron sputtering source including a first target having a surface from which material is sputtered and a first magnet assembly consisting of an array of single magnet bars that is rotatable about an axis of rotation with respect to said first target, said magnet assembly producing on said target an erosion profile that approximates a solution to an equation of the form ##EQU11## where e(r') is the erosion profile, t(r) is a desired radial thickness distribution of the sputtered film, K(r,r') is a function depending on the sputter geometry and process conditions, r is the radial position on the substrate, r' is the radial position on the target, and a and b are the radial limits of erosion on the target;
• a second magnetron sputtering source for forming a sputtered film on a second surface of said substrate, said second magnetron sputtering source including a second target having a surface from which material is sputtered and a second magnet assembly consisting of an array of single magnet bars that is rotatable about an axis of rotation with respect to said second target, said magnet assembly producing on said target an erosion profile that approximates a solution to an equation of the form ##EQU12## where e(r') is the erosion profile, t(r) is a desired radial thickness distribution of the sputtered film, K(r,r') is a function depending on the sputter geometry and process conditions, r is the radial position on the substrate, r' is the radial position on the target, and a and b are the radial limits of erosion on the target, said first and second magnet assemblies producing on the surfaces of said first and second targets plasma tracks, each having a shape characterized by a pair of symmetrical lobes, a deeply indented first inward cusp located near the axis of rotation and a moderately indented second inward cusp, said first and second cusps being located on opposite sides of said plasma track, each of said lobes having a relatively long section of substantially constant radius with respect to the axis of rotation;
• and
• a vacuum system for producing a vacuum in regions between each target surface and the substrate.