Isolation of incompatible processes in a multi-station processing chamber

• US 6,319,553 B1
• Filed: 02/28/2000
• Issued: 11/20/2001
• Est. Priority Date: 10/08/1998
• Status: Expired due to Term

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Hancock, Shawn D., Pratt, Thomas M., McInerney, Edward J.
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US09/514,469
• Time in Patent Office: 631 Days
• Field of Search: 118/719, 118/730, 427/250, 427/255.5, 427/255.7, 427/294, 427/301, 427/337
• US Class Current: 427/250
• CPC Class Codes: C23C 16/4412 Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps
• CPC Class Codes: C23C 16/45519 Inert gas curtains
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/4585 Devices at or outside the perimeter of the substrate support, e.g. clamping rings, shrouds
• CPC Class Codes: C23C 16/54 Apparatus specially adapted for continuous coating
• CPC Class Codes: H01L 21/6719 characterized by the construction of the processing chambers, e.g. modular processing chambers
• CPC Class Codes: H01L 21/67196 characterized by the construction of the transfer chamber

Abstract

A multi-station processing chamber in which incompatible processes are performed includes multiple pedestals positioned in wells with annular gaps around the pedestals. Showerheads located above the pedestals flow reactive gases over substrates located on the pedestals. The reactive gases are drawn through the annular gaps by a pressure gradient. The reactive gases are then pumped out of the wells through an exhaust port. The narrow annular gap permits little recirculation of the reactive gases one they are drawn into the wells. Moreover, the showerheads are flush with ceiling of the chamber and the wells contain smooth contours to minimize dead space in the chamber thereby reducing residence time of the reactive gases. An indexing plate is used to lift the substrates off the pedestals and to accurately position the substrates at the next processing station. In one embodiment a purge plate located on the ceiling of the chamber between the showerheads flows an inert gas, such as argon, to further assist in maintaining a separation between the reactive gases. Thus, while one process, such as a silane initiation is performed at one station, other stations may contemporaneously perform an incompatible process, such as a tungsten hexafluoride-silane nucleation process and hydrogen reduction, thereby increasing throughput.

Claims

1. A method of processing multiple substrates within a single chamber, said method comprising:

flowing a first gas supply over a second substrate at a first station within said chamber; and

flowing a second gas supply over a first substrate at a second station within said chamber;

providing a separation between said first gas supply and said second gas supply by flowing said first gas supply over said second substrate and into a first annular gap around said second substrate and out an exhaust port, and by flowing said second gas supply over said first substrate into a second annular gap around said first substrate and out said exhaust port.

2. The method of claim 1 wherein said first substrate is loaded into said chamber at said first station and moved to said second station prior to said second substrate being loaded into said chamber at said first station.

3. The method of claim 1 further comprising:

moving said second substrate and said first substrate, whereby said second substrate is positioned at said second station; and

flowing said second gas supply over said second substrate at said second station.

4. The method of claim 3, further comprising:

waiting for said first gas supply and said second gas supply to drain out of said chamber prior to moving said second substrate and said first substrate.

5. The method of claim 3 wherein moving said second substrate and said first substrate positions said first substrate at a third station within said chamber, said method further comprising:

flowing a third gas supply over said first substrate at said third station; and

providing a separation between said third gas supply and said first gas supply and said second gas supply by flowing said third gas supply over said first substrate and into a third annular gap around said first substrate and out said exhaust port.

6. The method of claim 3 further comprising:

loading a third substrate into said chamber at said first station after moving said second substrate and said first substrate;

heating said third substrate;

flowing said first gas supply over said third substrate at said first station; and

providing a separation between said first gas supply and said second gas supply by flowing said first gas supply over said third substrate and into said first annular gap around said third substrate and out said exhaust port, and by flowing said second gas supply over said second substrate into said second annular gap around said second substrate and out said exhaust port.

7. The method of claim 6, wherein said flow of a first gas supply at said first station is at least one of silane initiation, tungsten hexafluoride-silane nucleation and hydrogen reduction of tungsten hexafluoride.

8. The method of claim 6, wherein said flow of a second gas supply at said second station is at least one of silane initiation, tungsten hexafluoride-silane nucleation and hydrogen reduction of tungsten hexafluoride.

9. The method of claim 6, wherein said flow of a third gas supply at said third station is at least one of silane initiation, tungsten hexafluoride-silane nucleation and hydrogen reduction of tungsten hexafluoride.

10. The method of claim 6, said processing is tungsten deposition processing, and wherein said flow of a first gas supply at said first station is at least silane initiation, said flow of a second gas supply at said second station is at least a tungsten hexafluoride-silane nucleation, and said flow of a third gas supply at least said third station is a hydrogen reduction of tungsten hexafluoride.

11. The method of claim 10, further comprising a flow of said first gas supply at said second station as a continued silane initiation prior to flowing said second gas supply for tungsten hexafluoride-silane nucleation.

12. The method of claim 1, further comprising:

flowing a purging gas supply between said first station and said second station;

providing a separation between said first gas supply and said second gas supply by flowing said purging gas supply into said first annular gap and said second annular gap and out said exhaust port, said purging gas supply impedes said first gas supply and said second gas supply from combining.

13. The method of claim 12, wherein said first gas supply comprises a silane gas, said second gas supply comprises a tungsten hexafluoride gas, and said purging gas supply comprises an argon gas.