Double slit-valve doors for plasma processing

• US 6,192,827 B1
• Filed: 07/03/1998
• Issued: 02/27/2001
• Est. Priority Date: 07/03/1998
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Carducci, James D., Salimian, Siamak, Lee, Evans Y., Welch, Michael D., Luscher, Paul E., Shan, Homgqing
• Primary Examiner(s): Dang, Thi
• Assistant Examiner(s): Zervigon, Rudy
• Application Number:
  US09/111,251
• Time in Patent Office: 970 Days
• Field of Search: 414/217, 392/418, 118/728, 219/121.43, 204/415, 493/80
• US Class Current: 118/723.00E
• CPC Class Codes: H01J 2237/186 Valves
• CPC Class Codes: H01J 37/32458 Vessel
• CPC Class Codes: H01L 21/67011 Apparatus for manufacture or treatment processes H01L21/30, H01L21/46; for production or after-treatment of single crystals or homogeneous polycrystalline material C30B35/00
• CPC Class Codes: Y10S 156/916 Differential etching apparatus including chamber cleaning means or shield for preventing deposits
• CPC Class Codes: Y10S 414/139 including wafer charging or discharging means for vacuum chamber

Abstract

In a substrate vacuum processing chamber, a second inner slit passage door apparatus and method to supplement the normal slit valve and its door at the outside of the chamber. The inner slit passage door, blocks the slit passage at or adjacent the substrate processing location in a vacuum processing chamber to prevent process byproducts from depositing on the inner surfaces of the slit passage beyond the slit passage door and improves the uniformity of plasma in the processing chamber by eliminating a large cavity adjacent to the substrate processing location into which the plasma would otherwise expand. The inner slit passage door is configured and positioned in such a way as to avoid generating particles from the opening and closing motion of the second slit valve door, as it does not rub against any element of the chamber during its motion and the inner slit passage door is positioned with a predetermined gap from adjacent pieces and the door configuration includes beveled surfaces to further reduce the chance for particle generation, even when there is deposition of process byproducts on the door and its adjacent surfaces.

Claims

1. A plasma processing chamber for confining a substrate processing plasma envelope, said chamber comprising:

a substrate support to position a substrate at a substrate processing location to be exposed to said substrate processing plasma envelope;

a substrate transfer passageway extending through a wall of said chamber from an outside surface of said chamber to a position adjacent said substrate support;

an outer slit valve door at an outer position of said substrate transfer passageway to selectively vacuum-seal said transfer passageway and chamber during plasma processing; and

an inner slit passage door at an inner position of said passageway to exclude said passageway from exposure to said plasma envelope during plasma processing.

2. The plasma processing chamber as in claim 1,

wherein said inner slit passage door, when positioned to block said substrate transfer passageway, extends beyond the edges of said passageway by an overlap distance.

3. The plasma processing chamber as in claim 2,

wherein said overlap distance is at least ¼

inch (6.35 mm).

4. The plasma processing chamber as in claim 2,

wherein said overlap distance is approximately ½

inch (12.7 mm).

5. The plasma processing chamber as in claim 1,

wherein said inner slit passage door is curved to match the configuration of a chamber liner.

6. The plasma processing chamber as in claim 2,

wherein said inner slit passage door is curved to match the configuration of a chamber liner.

7. The plasma processing chamber as in claim 3,

wherein said inner slit passage door is curved to match the configuration of a chamber liner.

8. The plasma processing chamber as in claim 1,

wherein a movement of said inner slit passage door is in a vertical direction and is selectively controlled through movement of a bellows assembly through which a support for said inner slit passage door is provided.

9. The plasma processing chamber as in claim 8,

wherein said inner slit passage door is supported by two support rods.

10. The plasma processing chamber as in claim 9,

where a first of said two support rods is fixed to said inner slit passage door through a tightly clamped connection, while a second of said two support rods is connected to said inner slit passage door through a floating connection which maintains said inner slit valve door'"'"'s orientation in a vertical direction and in a direction approximately perpendicular to a long axis of said door, and is allowed to move in a direction approximately along said long axis of said door.

11. The plasma processing chamber as in claim 1,

wherein said inner slit passage door in a closed position is located with a gap of several ten thousandths of an inch from a surface adjacent an opening of said substrate transfer passageway.

12. The plasma processing chamber as in claim 8,

wherein the limit of the movement of said inner slit passage door in a vertical direction is precisely set by at least one soft stop.

13. The plasma processing chamber as in claim 2,

wherein top and bottom portions of said inner slit passage door are beveled to match opposed portions of a portion of a surface of the chamber that they face.

14. The plasma processing chamber as in claim 13,

wherein a center portion of said inner slit passage door is beveled to match an angled surface of a portion of a surface of said chamber through which said substrate transfer passageway extends.

15. The plasma processing chamber as in claim 1,

wherein said inner slit passage door and said outer slit valve door open simultaneously to allow passage of a substrate in to and out of the chamber.

16. A plasma processing chamber for confining a substrate plasma envelope, as in claim 1,

wherein said outer slit valve door is disposed between the plasma processing location and a transfer chamber located outside said processing chamber at an end of said substrate transfer passageway.