Low contamination high density plasma etch chambers and methods for making the same

• US 6,129,808 A
• Filed: 09/25/1998
• Issued: 10/10/2000
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Kennedy, William S., Wicker, Thomas E., Maraschin, Robert A.
• Primary Examiner(s): DANG, THI D
• Application Number:
  US09/161,074
• Time in Patent Office: 746 Days
• Field of Search: 156/345, 118/723 R, 118/723 E, 118/728, 204/298.02, 204/298.31, 204/298.15, 204/298.34
• US Class Current: 156/345.1
• CPC Class Codes: H01J 2237/022 Avoiding or removing foreign or contaminating particles, debris or deposits on sample or tube
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32477 characterised by the means for protecting vessels or internal parts, e.g. coatings
• CPC Class Codes: Y10S 156/914 Differential etching apparatus including particular materials of construction
• CPC Class Codes: Y10S 156/916 Differential etching apparatus including chamber cleaning means or shield for preventing deposits
• CPC Class Codes: Y10T 428/12347 Plural layers discontinuously bonded [e.g., spot-weld, mechanical fastener, etc.]

Abstract

A high density plasma processing chamber including an electrostatic chuck for holding a wafer, and consumable parts that are highly etch resistant, less susceptible to generating contamination and temperature controllable is disclosed. The consumable parts include a chamber liner having a lower support section and a wall that is configured to surround the electrostatic chuck. The consumable parts also include a liner support structure having a lower extension, a flexible wall, and an upper extension. The flexible wall is configured to surround an external surface of the wall of the chamber liner, and the liner support flexible wall is spaced apart from the wall of the chamber liner. The lower extension of the liner support is however, configured to be in direct thermal contact with the lower support section of the chamber liner. Additionally, a baffle ring is part of the consumable parts, and is configured to be assembled with and in thermal contact with the chamber liner and the liner support. A heater is capable of being thermally connected to the liner support for thermally conducting a temperature from the liner support to the chamber liner and the baffle ring. In a most preferred embodiment, the chamber liner and the baffle ring are made from materials that are innocuous to materials on the wafer being etched. In this manner, once these materials are exposed to the energy of the high density plasma sputtering, volatile products will be produced that are substantially similar to volatile etch products produced during the etching of surface layers of the wafer. These volatile products can then be removed from the chamber.

Claims

1. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts, comprising:

a chamber liner having a lower support section and a wall that is configured to surround the electrostatic chuck; and

a liner support structure having a lower extension, a flexible wall, and an upper extension, the flexible wall being configured to surround an external surface of the wall of the chamber liner, the flexible wall being spaced apart from the wall of the chamber liner, but the lower extension of the liner support being in direct thermal contact with the lower support section of the chamber liner.

2. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, further comprising:

a heater being thermally connected to the upper extension of the liner support for thermally conducting a temperature from the liner support to the chamber liner.

3. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 2, wherein the liner support is made from a flexible aluminum material.

4. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 3, wherein the flexible wall has a plurality of fingers to enable the flexible wall to absorb a stress imposed by the temperature.

5. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 4, wherein the lower extension of the liner support is maintained fixed to the lower support section of the chamber liner while the upper extension of the liner support is capable of flexing outwardly from a center of the wall of the chamber liner, while relieving stress on the chamber liner.

6. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, further comprising:

a baffle ring being configured to be assembled with and in thermal contact with the chamber liner and the liner support, the baffle ring defining a plasma screen around the electrostatic chuck.

7. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 6, wherein the baffle ring is made from materials consisting of one or more of:

silicon carbide (SiC), silicon nitride (Si₃ N₄), boron carbide (B₄ C), and boron nitride (BN).

8. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, wherein the chamber liner is made from materials consisting of one or more of:

silicon carbide (SiC), silicon nitride (Si₃ N₄), boron carbide (B₄ C), and boron nitride (BN).

9. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, wherein the chamber liner has a low resistivity and is configured to provide an RF path to ground.

10. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, further comprising:

a gas distribution plate defined over the electrostatic chuck, the gas distribution plate being configured to have a high resistivity.

11. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 10, wherein the gas distribution plate is made from materials consisting of one or more of:

silicon carbide (SiC), silicon nitride (Si₃ N₄), boron carbide (B₄ C), and boron nitride (BN).

12. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, further comprising:

a focus ring and a pedestal for holding the focus ring and electrostatic chuck.

13. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 12, wherein the focus ring and the pedestal is made from materials consisting of one or more of:

silicon carbide (SiC), silicon nitride (Si₃ N₄), boron carbide (B₄ C), and boron nitride (BN).

14. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, wherein the consumable parts include the chamber liner, the liner support, a baffle ring, a focus ring, a pedestal, and a gas distribution plate, the consumable parts are made form materials consisting of one or more of:

silicon carbide (SiC), silicon nitride (Si₃ N₄), boron carbide (B₄ C), and boron nitride (BN).

15. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 14, wherein the wafer has a layer of oxide that is configured to be etched under a high density plasma etch process.

16. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 1, further comprising:

an outer support being thermally connected to the lower extension of the liner support structure;

a top plate configured to mount over the plasma processing chamber, the outer support being in thermal contact with the top plate.

17. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 16, further comprising:

a cooling ring being in thermal contact with the top plate, such that the cooling ring is connected by a thermal path to the liner support structure and the chamber liner.

18. A plasma processing chamber having an electrostatic chuck for holding a wafer, the plasma processing chamber having consumable parts as recited in claim 17, wherein the cooling ring is configured to prevent the chamber liner from drifting upwards in a temperature during plasma processing.

19. A plasma etching chamber, comprising:

a chamber liner having a lower support section and a cylindrical wall that surrounds a center of the plasma etching chamber;

a liner support being configured to surround the chamber liner, the liner support is spaced apart from the cylindrical wall of the chamber liner and is thermally connected to the lower support section of the chamber liner, the liner support further includes a plurality of slots that divide the liner support into a plurality of fingers.

20. A plasma etching chamber as recited in claim 19, wherein the chamber liner is made from a material including one of a silicon carbide (SiC) material, a silicon nitride (Si₃ N₄) material, a boron carbide (B₄ C) material, and a boron nitride (BN) material, and the liner support is made from an aluminum material.

21. A plasma etching chamber as recited in claim 19, wherein the liner support further includes:

an upper extension;

a flexible wall; and

a lower extension;

wherein the flexible wall and the lower extension have the plurality of slots that define the plurality of fingers in the liner support.

22. A plasma etching chamber as recited in claim 21, wherein the upper extension is configured to receive a cast heater ring, such that the cast heater ring is thermal contact with the liner support, and the liner support is capable of thermally conducting a temperature to the chamber liner.

23. A plasma etching chamber as recited in claim 22, wherein the upper extension of the liner support is configured to expand away from the chamber liner when exposed to a sufficient level of the temperature by the cast heater ring.

24. A plasma etching chamber as recited in claim 19, further comprising:

a baffle ring being made from a material including one of a silicon carbide (SiC) material, a silicon nitride (Si₃ N₄) material, a boron carbide (B₄ C) material, and a boron nitride (BN) material, and the baffle ring is thermally connected to the lower extension of the liner support and the lower support section of the chamber liner.

25. A plasma etching chamber as recited in claim 21, further comprising:

an outer support being thermally connected to the lower extension of the liner support structure;

a top plate configured to mount over the plasma etching chamber, the outer support being in thermal contact with the top plate.

26. A plasma etching chamber as recited in claim 25, further comprising:

a cooling structure being in thermal contact with the top plate, such that the cooling structure is connected by a thermal path to the liner support and the chamber liner.

27. A plasma etching chamber as recited in claim 26, wherein the cooling structure is configured to prevent the chamber liner from drifting upwards in a temperature during etching.

28. A plasma etching chamber as recited in claim 23, further comprising:

a gas distribution plate being made from a material including one of a silicon carbide (SiC) material, a silicon nitride (Si₃ N₄) material, a boron carbide (B₄ C) material, and a boron nitride (BN) material, and the material of the gas distribution plate is configured to be highly resistive.

29. A plasma etching chamber as recited in claim 20, wherein the chamber liner is configured to be grounded and have a low surface resistivity.

30. A plasma etching chamber as recited in claim 29, wherein the chamber liner provides an RF path to a ground potential.

31. A plasma etching chamber as recited in claim 20, wherein a wafer is configured to be contained at the center of the plasma etching chamber, and the wafer has a layer of oxide that is configured to be etched under a high density plasma etch process.

32. A plasma etching chamber as recited in claim 20, further comprising:

a baffle ring, a focus ring, a pedestal, and a gas distribution plate, each of which are made from a material including one of a silicon carbide (SiC) material, a silicon nitride (Si₃ N₄) material, a boron carbide (B₄ C) material, and a boron nitride (BN) material.

33. A method for making consumable parts for use in a high density plasma etching chamber, comprising:

generating a chamber liner from a material selected from one of a silicon carbide (SiC) material, a silicon nitride (Si₃ N₄) material, a boron carbide (B₄ C) material, and a boron nitride (BN) material, the chamber liner having a wall that surrounds a plasma region of the chamber and a lower support section;

generating an aluminum liner support, the liner support having a lower extension, a flexible wall and an upper extension;

machining a plurality of slots into the flexible wall and the lower extension of the liner support to enable the liner support to expand under elevated temperatures;

generating a baffle ring from the material selected from one of the silicon carbide (SiC) material, the silicon nitride (Si₃ N₄) material, the boron carbide (B₄ C) material, and the boron nitride (BN) material;

machining a plurality of slots into the baffle ring to define a plasma screen; and

connecting the chamber liner, the liner support and the baffle ring together at a thermal conduction interface, such that a thermal contact exists between the chamber liner, the liner support and baffle ring.

34. A method for making consumable parts for use in a high density plasma etching chamber as recited in claim 33, further comprising:

attaching a heater ring to the upper extension of the liner support;

wherein the heater ring is configured to conduct a temperature to the liner support and then transfer the temperature to the chamber liner and the baffle ring through the thermal conduction interface.

35. A method for making consumable parts for use in a high density plasma etching chamber as recited in claim 33, further comprising:

striking a plasma in the high density plasma etching chamber, the plasma is configured to come into contact with the chamber liner that will produce volatile products, the volatile products being substantially similar to a volatile etch produced when surfaces of a wafer being processed in the chamber is etched.

36. A method for making consumable parts for use in a high density plasma etching chamber as recited in claim 35, wherein the volatile products and the volatile etch products are vacuum removed from the chamber.

37. A method for making consumable parts for use in a high density plasma etching chamber as recited in claim 35, further comprising:

generating a baffle ring;

generating a focus ring;

generating a pedestal; and

generating a gas distribution plate;

wherein each of which are made from a material including one of a silicon carbide (SiC) material, a silicon nitride (Si₃ N₄) material, a boron carbide (B₄ C) material, and a boron nitride (BN) material.

38. A method for making consumable parts for use in a high density plasma etching chamber as recited in claim 35, wherein the chamber liner provides a low resistive RF path to ground.