Ganged scanning of multiple magnetrons, especially two level folded magnetrons

Patent metadata

Field	Value
Publication number	US-8961756-B2
Application number	US-78075707-A
Country	US
Kind code	B2
Filing date	Jul 20, 2007
Priority date	Aug 4, 2006
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

A magnetron assembly including one or more magnetrons each forming a closed plasma loop on the sputtering face of the target. The target may include multiple strip targets on which respective strip magnetrons roll and are partially supported on a common support plate through a spring mechanism. The strip magnetron may be a two-level folded magnetron in which each magnetron forms a folded plasma loop extending between lateral sides of the strip target and its ends meet in the middle of the target. The magnets forming the magnetron may be arranged in a pattern having generally uniform straight portions joined by curved portion in which extra magnet positions are available near the corners to steer the plasma track. Multiple magnetrons, possibly flexible, may be resiliently supported on a scanned support plate and individually partially supported by rollers on the back of one or more targets.

First claim

The invention claimed is:

1. A two-level folded magnetron including an outer magnetic pole of one polarity surrounding an inner magnetic pole of another polarity at least partially opposed to the one polarity and separated therefrom by a gap extending in a closed path, the path including two generally parallel sub-paths each extending from a head to a tail thereof along a respective folded pattern including a first straight portion extending form the head to a first 180° corner, a second straight portion extending from the first 180° corner to a second 180° corner, and a third straight portion extending from the second 180° corner to the tail, both the first and third straight portions of each of the two sub-paths extending along a respective axis common to the first and third straight portions and parallel to the corresponding second straight portion, wherein the head comprises a third 180° corner linking and extending between ends of the two respective first straight portions of the two sub-paths and the tail comprises a fourth 180° corner linking and extending between ends of the two respective third straight portions of the two sub-paths.

2. The magnetron of claim 1 , wherein the inner pole includes a straight portion and an acute portion and wherein at least one of the 180° corners includes a tear-drop shape which flares outwardly from a tip of the acute portion and thereafter flares inwardly toward two of the straight portions, wherein the tear-drop shape reduces hot spots at the acute portion.

3. The magnetron of claim 2 , wherein interior portions of the tear-drop shape are not populated with magnets but peripheral portions of the tear-drop shape are populated with magnets.

4. The magnetron of claim 1 , wherein a linear density of magnetic strength in the outer pole one pole adjacent one of the 180° corners is greater than a linear density of magnetic strength of the inner pole adjacent the one 180° corner.

5. The magnetron of claim 1 , further including means to move a centerline of a resultant plasma track from a convex portion of the gap towards a concave portion of the gap.

6. A magnetron assembly comprising:
a plurality of the two-level folded magnetrons of claim 1 ;
a movable rigid support structure supporting the plurality of the two-level folded magnetrons; and
respective resilient supports between the support structure and the plurality of the two-level folded magnetrons to partially support respective ones of each of the two-level folded magnetrons.

7. The magnetron of claim 6 , wherein the resilient supports comprise respective tension springs partially and resiliently supporting respective ones of the two-level folded magnetrons.

8. The magnetron of claim 1 , wherein first ones of the first and second straight portions of the two sub-paths extend along a first axis and second ones of the first and second straight portions of the two sub-paths extend along a second axis parallel to but displaced from the first axis, whereby the head and tail are adjacent each other.

9. The magnetron of claim 1 , wherein the third 180° corner extends between ends of the two respective first straight portions of the two sub-paths to thereby link the two respective straight portions of the two sub-paths and the fourth 180° corner extends between ends of the two respective third straight portions of the two sub-paths to thereby link the two respective straight portions of the two sub-paths.

10. A magnetron including an outer magnetic pole of one polarity surrounding an inner magnetic pole of an at least partially opposed polarity and separated therefrom by a gap extending in a closed path including a gap corner between a convex corner of one pole and a concave corner of the other pole, further comprising magnets of a first magnetic strength defining each of a plurality of straight portions of the two poles and magnets of a second and stronger magnetic strength at least partially defining the convex corner.

11. The magnetron of claim 10 , wherein the magnets of the first magnetic strength define the concave corner.

12. A magnetron, comprising first magnets of a first magnetic polarity and second magnets of a second magnetic polarity at least partially opposed to the first magnetic polarity and surrounding the first magnets and separated therefrom by a gap arranged in a closed pattern having parallel straight portions connected by curved portions, wherein the first and second magnets are arranged substantially uniformly in the straight portions and are arranged in non-uniform arrangement in the curved portions compared to a uniform arrangement having one or two rows of magnets arranged along sides of the gap.

13. The magnetron of claim 12 , wherein in the curved portions more magnets are arranged on a convex side of the gap than on the concave side compared to an arrangement having one or two rows of magnets arranged alongside the gap.

14. A ganged magnetron, comprising:
a movable rigid support structure;
a plurality of magnetic plates disposed below the support structure and separately, resiliently, and partially supported from above by the support structure; and
a plurality of magnet arrangements having a closed path formed between magnetic poles of opposite polarities and separately supported by respective ones of the magnetic plates, wherein each of the magnet arrangements comprises a two-level folded magnetron including an outer magnetic pole of one polarity surrounding an inner magnetic pole of another polarity at least partially opposed to the one polarity and separated therefrom by a gap extending in a closed path, the path including two generally parallel sub-paths each extending from a head to a tail thereof along a respective folded pattern each including a first straight portion extending from the head to a first 180° corner, a second straight portion extending from the first 180° corner to a second 180° corner, and a third straight portion extending from the second 180° corner to the tail, both the first and third straight portions of each of the two sub-paths extending along a respective axis common to the first and third straight portions and parallel to the corresponding second straight portion, wherein the head comprises a third 180° corner linking the two first straight portions of the two sub-paths and the tail comprises a fourth 180° corner linking and extending between ends of the two straight portions of the two sub-paths.

Assignees

• Inagawa Makoto
• Le Hien Minh Huu
• Hosokawa Akihiro
• Stimson Bradley O
• White John M
• Applied Materials Inc

Inventors

• Inagawa Makoto
• Le Hien Minh Huu
• Hosokawa Akihiro
• Stimson Bradley O
• White John M

Classifications

• H01J37/3455

  Movable magnets · CPC title

• H01J37/3408 Primary

  Planar magnetron sputtering · CPC title