Cylindrical magnetron with self cleaning target

• US 20040163943A1
• Filed: 02/21/2003
• Published: 08/26/2004
• Est. Priority Date: 02/21/2003
• Status: Active Grant

• Current Assignee: Von Ardenne Anlagentechnik GmbH
• Original Assignee: Von Ardenne Anlagentechnik GmbH
• Inventors: Johnson, Kevin D., Rietzel, James G.
• Granted Patent: US 7,014,741 B2
• Time in Patent Office: Days
• US Class Current: 204/192.12
• CPC Class Codes: H01J 37/3405 Magnetron sputtering

Abstract

A cylindrical magnetron capable of running at high current and voltage levels with a target tube that is self cleaning not only in the center portion, but also at the ends. Sputtering the ends of the target tube virtually eliminates accumulation of condensate at the ends and any resultant arcing, resulting in a more reliable magnetron requiring less service and a magnetron that produces more consistent coatings.

Claims

1. A magnetron having endblocks, the magnetron comprising:

a cylindrical target tube comprising a material to be sputtered onto a substrate, a portion of the target tube within the endblocks and an exposed portion without the endblocks;

support structures located at the ends of the target tube that position the target tube and supply cooling water and power to the target tube; and

a magnetic structure within the target tube, the magnetic structure having a magnetic field that extends the length of the exposed portion of the target tube.

2. The magnetron of claim 1 wherein the magnetic field is of sufficient strength along the entire length of the target tube to sputter along the entire length of the target tube.

3. The magnetron of claim 1 wherein the magnetron target tube is self cleaning, thereby minimizing the deleterious effects of electrical arcing.

4. The magnetron of claim 1 wherein the magnetic structure has a higher magnetic field density at the ends of the structure compared to the central portion of the structure, and wherein the target tube comprises an additional amount of material positioned about the ends of the target tube.

5. The magnetron of claim 1 wherein the additional amount of material comprises the same material as the material to be sputtered onto the substrate.

6. The, magnetron of claim 1 wherein the additional amount of material comprises a different material than the material to be sputtered onto the substrate.

7. The magnetron of claim 6 wherein the different material has a lower sputtering rate than the material to be sputtered and extends the life of the target tube.

8. The magnetron of claim 5 wherein the additional amount of material is integrally formed with the target.

9. The magnetron of claim 1 wherein the additional amount of material is in the form of a collar ring attached to the target tube.

10. A cylindrical magnetron comprising:

a cylindrical target tube comprising a material to be sputtered onto a substrate;

support structures located at the ends of the target tube that position the target tube and supply cooling water and power to the target tube;

a magnetic array within the target tube, the magnetic array positioned within the target tube such that the target tube is self cleaning.

11. The magnetron of claim 10 wherein the magnetic array has a higher magnetic field density at the ends of the array compared to the central portion of the array, and wherein an additional amount of material is positioned about the target tube adjacent the higher magnetic field density.

12. The magnetron of claim 11 wherein the magnetron has an allowable substrate width, and wherein the additional amount of material is positioned such that it will be sputtered outside the allowable width and will not be substantially deposited upon the substrate.

13. The magnetron of claim 11 wherein less than one percent of a primary component of the additional material is deposited upon the substrate.

14. The magnetron of claim 11 wherein the additional material is different than the material to be sputtered.

15. The magnetron of claim 10 wherein condensate at the target tube ends is minimized to a level sufficient to prevent arcing at the target tube ends.

16. A magnetron comprising:

a target tube;

means for supporting the target tube;

means for rotating the target tube;

means for sputtering material from the target tube along the entire exposed length of the target tube.

17. The magnetron of claim 16 wherein the means for sputtering material is configured such that the only portion of the target tube that is not sputtered is inside the means for supporting the target tube.

18. The magnetron of claim 16 further comprising means for extending the usable life of the target tube.

19. A method for preventing arcing in a magnetron, improving the coatings deposited upon a substrate, and increasing the efficiency of the magnetron, the method comprising:

providing a cylindrical target tube, the target tube having a length;

providing a magnet having a magnetic field;

positioning the magnet within the target tube such that the magnetic field extends along the length of the target tube and such that the center and the ends of the target tube are sputtered during sputtering operations.

20. The method of claim 19 wherein the entire target tube is self cleaning.

21. The method of claim 19 wherein arcing from the target is eliminated.

22. The method of claim 19 further comprising providing additional material at high sputtering rate areas of the target tube.

23. A cylindrical target tube comprising a material to be sputtered onto a substrate and a magnetic array within the target tube, the target tube clamped at the ends to support structures, the magnetic array positioned within the target tube such that the entire unclamped portion of target tube is sputtered.

24. A cylindrical magnetron with a target tube that is self cleaning not only in the center portion, but also at the ends.