Gas distribution plate assembly for plasma reactors

• US 20050150601A1
• Filed: 01/12/2004
• Published: 07/14/2005
• Est. Priority Date: 01/12/2004
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Axcelis Technologies Incorporated
• Inventors: Srivastava, Aseem K.
• Granted Patent: US 7,892,357 B2
• Time in Patent Office: Days
• US Class Current: 156/345.330
• CPC Class Codes: H01J 2237/3342 Resist stripping
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01L 21/67017 Apparatus for fluid treatment H01L21/67126, H01L21/6715 take precedence
• CPC Class Codes: H01L 21/67115 mainly by radiation

Abstract

A baffle plate assembly for distributing gas flows into an adjacent process chamber containing a semiconductor wafer to be processed includes a planar gas distribution portion having a plurality of apertures therein; a flange surrounding the gas distribution portion; and an impingement device centrally attached to the gas distribution portion, wherein the device includes a cap and a stem, the stem being in thermal contact with the gas distribution portion. Also disclosed herein are plasma reactors employing the baffle plate assembly and methods for reducing recombination of species in a plasma.

Claims

1. A baffle plate assembly for distributing gas flows into an adjacent process chamber containing a semiconductor wafer to be processed, comprising:

a planar gas distribution portion having a plurality of apertures therein;

a flange surrounding the gas distribution portion; and

an impingement device centrally attached to the gas distribution portion, wherein the device includes a cap and a stem, the stem being in thermal contact with the gas distribution portion.

2. The baffle plate assembly of claim 1, wherein the gas distribution portion, the flange, and the impingement device are fabricated from aluminum.

3. The baffle plate assembly of claim 1, wherein the gas distribution portion, the flange, and the impingement device are fabricated from quartz.

4. The baffle plate assembly of claim 1, wherein the gas distribution portion, the flange, and the impingement device are fabricated from sapphire coated quartz.

5. The baffle plate assembly of claim 1, wherein the cap has a planar impingement surface.

6. The baffle plate assembly of claim 1, wherein the cap has an angled impingement surface.

7. The baffle plate assembly of claim 1, wherein the cap has a substantially triangular cross sectional shape.

8. The baffle plate assembly of claim 1, wherein the cap has a concave surface.

9. The baffle plate assembly of claim 1, wherein the cap has a convex surface.

10. The baffle plate assembly of claim 1 ,wherein the plurality of apertures of the gas distribution portion have a frustoconical portion extending from a top surface to about a midpoint of the gas distribution portion and a substantially straight portion extending from the midpoint to a bottom surface of the gas distribution portion.

11. The baffle plate assembly of claim 1, wherein the gas distribution portion further comprises cooling passages machined therein for circulating a cooling medium therethrough.

12. The baffle plate assembly of claim 1, wherein the cap has a diameter about equal to a diameter of the process chamber opening.

13. A downstream plasma asher comprising:

a plasma generator;

a process chamber downstream from the plasma generator, the process chamber comprising an opening for receiving plasma from the plasma generator into the process chamber, and a substrate supported within the process chamber; and

a baffle plate assembly intermediate the substrate and the process chamber opening for distributing plasma flow in the process chamber, the baffle plate assembly comprising a planar gas distribution portion having a plurality of apertures therein;

a flange surrounding the gas distribution portion; and

an impingement device centrally attached to the gas distribution portion, wherein the device includes a cap and a stem, the cap having a diameter about equal to a diameter of the process chamber opening and the stem in thermal contact with the gas distribution portion.

14. The downstream plasma asher of claim 13, wherein the plasma generator is a selected from the group consisting of microwave plasma generator, a radiofrequency plasma generator, or a combination thereof.

15. The downstream plasma asher of claim 13, wherein the impingement device is removable.

16. The downstream plasma asher of claim 13, wherein the gas distribution portion, the flange, and the impingement device are fabricated from aluminum.

17. The downstream plasma asher of claim 13, wherein the gas distribution portion, the flange, and the impingement device are fabricated from quartz.

18. The downstream plasma asher of claim 13, wherein the gas distribution portion, the flange, and the impingement device are fabricated from sapphire coated quartz.

19. The downstream plasma asher of claim 13, wherein the cap has a planar impingement surface.

20. The downstream plasma asher of claim 13, wherein the cap has an angled impingement surface.

21. The downstream plasma asher of claim 13, wherein the cap has a substantially triangular cross sectional shape.

22. The downstream plasma asher of claim 13, wherein the cap has a concave surface.

23. The downstream plasma asher of claim 13, wherein the cap has a convex surface.

24. The downstream plasma asher of claim 13, wherein the plurality of apertures of the gas distribution portion have a frustoconical portion extending from a top surface to about a midpoint of the gas distribution portion and a substantially straight portion extending from about the midpoint to a bottom surface of the gas distribution portion.

25. The downstream plasma asher of claim 13, wherein the gas distribution portion further comprises cooling passages machined therein for circulating a cooling medium therethrough.

26. The downstream plasma asher of claim 13, wherein a diameter of the gas distribution portion is about equal to a diameter of the substrate.

27. A process for minimizing recombination of species in a plasma ashing process, comprising:

installing a baffle plate assembly intermediate a plasma generating region and a substrate to be processed, the baffle plate assembly comprising a planar gas distribution portion having a plurality of apertures therein;

a flange surrounding the gas distribution portion; and

an impingement device centrally attached to the gas distribution portion, wherein the impingement device includes a cap and a stem, the stem being in thermal contact with the gas distribution portion; and

flowing plasma through and about the baffle plate assembly and onto the substrate.

28. The process according to claim 27;

further comprising cooling the baffle plate assembly by flowing a cooling medium through cooling passages disposed in the gas distribution portion of the baffle plate assembly.

29. The process according to claim 27, wherein the cap has a diameter about equal to a diameter of the process chamber opening.

30. The process according to claim 27, wherein the gas distribution portion, the flange, and the impingement device are fabricated from quartz.

31. The downstream plasma asher of claim 27, wherein the gas distribution portion, the flange, and the impingement device are fabricated from sapphire coated quartz.

32. The process according to claim 27, wherein the gas distribution portion, the flange, and the impingement device are fabricated from aluminum.