GROUND SHIELD WITH REENTRANT FEATURE

• US 20070295602A1
• Filed: 06/27/2006
• Published: 12/27/2007
• Est. Priority Date: 06/27/2006
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Miller, Keith A., Cox, Michael S., Subramani, Anantha, Tiller, Jennifer W.
• Granted Patent: US 7,718,045 B2
• Time in Patent Office: Days
• US Class Current: 204/298.11
• CPC Class Codes: H01J 2237/0206 Extinguishing, preventing or controlling unwanted discharges
• CPC Class Codes: H01J 2237/026 Shields
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/3405 Magnetron sputtering

Abstract

The invention generally provides a ground shield for use in a physical vapor deposition (PVD) chamber. In one embodiment, a ground shield includes a generally cylindrical body comprising an outer wall, an inner upper wall, an inner lower wall having a diameter less than a diameter of the inner upper wall and a reentrant feature coupling the upper and inner lower walls. The reentrant feature advantageously prevents arching between the shield and target, which promotes greater process uniformity and repeatability along with longer chamber component service life.

Claims

1. A ground shield, comprising:

a generally cylindrical body comprising;

an outer wall;

an inner upper wall;

an inner lower wall having a diameter less than a diameter of the inner upper wall; and

a reentrant feature coupling the upper and inner lower walls.

2. The ground shield of claim 1, wherein the body is fabricated from stainless steel.

3. The ground shield of claim 1, wherein the body is fabricated from titanium.

4. The ground shield of claim 1, wherein the body is fabricated from or coated with a conductive material.

5. The ground shield of claim 1, wherein at least a portion of the body has a surface treatment.

6. The ground shield of claim 1, wherein at least a portion of the body has a bead blasted surface.

7. The ground shield of claim 1 further comprising:

a mounting flange extending from the outer wall.

8. The ground shield of claim 7, wherein the mounting flange further comprises:

a plurality of slots formed therein.

9. The ground shield of claim 8, wherein the body has a bead blasted surface except for the slots.

10. The ground shield of claim 8, wherein the slots are arranged in a polar array.

11. The ground shield of claim 9, wherein the slots have an end open through an outside wall of the flange.

12. The ground shield of claim 9, wherein the slots are orientated radially relative to a centerline of the body.

13. The ground shield of claim 1, wherein the inner upper wall is flared outward.

14. The ground shield of claim 1 further comprising:

a plurality of slots formed on a side of the ground shield opposite the reentrant feature.

15. The ground shield of claim 1, wherein the reentrant feature has a diameter greater than the diameter of an adjacent portion of the inner upper wall.

16. The ground shield of claim 15, wherein the reentrant feature has a diameter less than the diameter of an adjacent portion of the inner lower wall.

17. A ground shield, comprising:

a generally cylindrical body comprising;

an outer wall;

a mounting flange extending from the outer wall and having a plurality of radially orientated slots formed therein;

an inner upper wall flared outwards toward a top end of the body;

an inner lower wall defined at a bottom end of the body and having a diameter less than a diameter of the inner upper wall; and

a reentrant feature coupling the upper and inner lower walls, the reentrant feature extending downwards and outward from the inner upper wall.

18. The ground shield of claim 17, wherein at least a portion of the body has a bead blasted surface.

19. The ground shield of claim 17, wherein the body comprises at least one of stainless steel or titanium.

20. A ground shield, comprising:

a generally cylindrical stainless steel body comprising;

an outer wall;

an inner wall having upper and lower portions, the upper portion of the inner wall flared outwards toward a top end of the body and having a diameter greater than a diameter of the lower portion;

a mounting flange extending from the outer wall to outside wall and having a support surface facing a bottom end of the body;

a plurality of slots arranged in a polar array and formed in the support surface, the slots having an open end extending through the outside wall of the mounting flange; and

a reentrant feature extending downwards and outward from the upper portion of the inner wall and upwards and outwards from the lower portion of the inner wall.