Sputtering apparatus

A sputtering system comprising:

• a chamber through which a substrate moves;
• and
• a cathode assembly comprising:
• an elongated rotatable cylindrical tube mounted in the chamber and having a target surface;
• and
• a magnetron assembly positioned within the elongated rotatable cylindrical tube, the magnetron assembly comprising:
• a plurality of magnets configured to produce a plasma confinement path magnetic field on the target surface;
• and
• a yoke configured to hold the plurality of magnets in at least four straight, parallel, independent linear arrays;
• wherein the plurality of magnets is arranged on the yoke so as to form a pattern comprising an outer portion and an inner portion, wherein the outer portion substantially surrounds a perimeter of the inner portion;
• wherein end portions of the linear arrays comprise a pair of turnaround sections, wherein each turnaround section substantially spans respective ends of a pair of elongated sections of the outer portion;
• wherein the magnetic field produced by the inner portion is coupled to the magnetic field produced by the outer portion to form one continuous plasma confinement path;
• and
• wherein the magnets in each turnaround section are arranged to break up a turnaround curve formed by the one continuous plasma confinement path into two or more different curves that are offset from each other along a target rotation axis.

A method of sputtering material on a substrate, the method comprising:

• forming a pattern of magnets as a part of a magnetron assembly disposed within an elongated rotatable cylindrical tube, wherein the elongated rotatable cylindrical tube comprises a target surface;
• mounting the elongated rotatable cylindrical tube in a chamber;
• maintaining a vacuum in the chamber;
• rotating the elongated rotatable cylindrical tube within the chamber;
• supplying a magnetic flux at the target surface using the magnetron assembly;
• and
• moving the substrate within the chamber near the target surface;
• wherein the magnetron assembly comprises:
• a plurality of magnets configured to produce a plasma confinement path magnetic field on the target surface;
• and
• a yoke configured to hold the plurality of magnets in at least four straight, parallel, independent linear arrays;
• wherein the plurality of magnets is arranged on the yoke so as to form a pattern comprising an outer portion and an inner portion, wherein the outer portion substantially surrounds a perimeter of the inner portion;
• wherein end portions of the linear arrays comprise a pair of turnaround sections, wherein each turnaround section substantially spans respective ends of a pair of elongated sections of the outer portion;
• wherein the magnetic field produced by the inner portion is coupled to the magnetic field produced by the outer portion to form one continuous plasma confinement path;
• and
• wherein the magnets in each turnaround section are arranged to break up a turnaround curve formed by the one continuous plasma confinement path into two or more different curves that are offset from each other along a target rotation axis.