PLASMA-FACING PROBE ARRANGEMENT INCLUDING VACUUM GAP FOR USE IN A PLASMA PROCESSING CHAMBER

• US 20100007337A1
• Filed: 07/07/2009
• Published: 01/14/2010
• Est. Priority Date: 07/07/2008
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Booth, Jean-Paul, Keil, Douglas
• Granted Patent: US 8,547,085 B2
• Time in Patent Office: Days
• US Class Current: 324/149
• CPC Class Codes: G01R 19/0061 Measuring currents of particle-beams, currents from electron multipliers, photocurrents, ion currents; Measuring in plasmas
• CPC Class Codes: H01J 37/32541 Shape
• CPC Class Codes: H01J 37/32577 Electrical connecting means
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

An arrangement for measuring process parameters within a processing chamber is provided. The arrangement includes a probe arrangement disposed in an opening of an upper electrode. Probe arrangement includes a probe head, which includes a head portion and a flange portion. The arrangement also includes an o-ring disposed between the upper electrode and the flange portion. The arrangement further includes a spacer made of an electrically insulative material positioned between the head portion and the opening of the upper electrode to prevent the probe arrangement from touching the upper electrode. The spacer includes a disk portion configured for supporting an underside of the flange portion. The spacer also includes a hollow cylindrical portion configured to encircle the head portion. The spacer forms a right-angled path between the o-ring and an opening to the processing chamber to prevent direct line-of-sight path between the o-ring and the opening to the processing chamber.

Claims

1. An arrangement for measuring process parameters within a processing chamber of a plasma processing system comprising:

a probe arrangement disposed in an opening of an upper electrode, wherein said probe arrangement includes a probe head and said probe head includes

a head portion, wherein said head portion is a cylindrical plug with a plasma-facing surface and is positioned within said opening of said upper electrode, and

a flange portion, wherein said flange portion is a hollow cylindrical structure with a diameter larger than said head portion and is positioned above an upper surface of said upper electrode;

an o-ring disposed between said upper surface of said upper electrode and a bottom-facing surface of said flange portion of said probe head; and

a spacer made of an electrically insulative material positioned between a vertical sidewall of said head portion of said probe head and a vertical sidewall of said opening of said upper electrode to prevent said probe arrangement from touching said upper electrode when said probe arrangement is inserted into said opening of said upper electrode, wherein said spacer includes

a disk portion configured at least for supporting an underside of said flange portion of said probe head, and

a hollow cylindrical portion configured to encircle said head portion of said probe head, wherein said hollow cylindrical portion has a smaller diameter than said disk portion,

wherein said spacer forms a right-angled path between said o-ring and an opening to said processing chamber, thereby preventing a direct line-of-sight path between said o-ring and said opening to said processing chamber.

2. The arrangement of claim 1 wherein said probe arrangement is an ion flux probe.

3. The arrangement of claim 1 wherein said probe head is made from silicon.

4. The arrangement of claim 1 wherein said plasma-facing surface of said probe head is flushed with a plasma-facing surface of said upper electrode.

5. The arrangement of claim 1 wherein said spacer is made from silicon nitride (SiN).

6. The arrangement of claim 1 wherein said spacer form a high aspect ratio gap between said vertical sidewall of said head portion and said vertical sidewall of said opening of said upper electrode, wherein said high aspect ratio gap has a vertical length greater than a horizontal width.

7. The arrangement of claim 1 wherein said probe head is in electrical contact with a socket made of an electrically conductive material.

8. The arrangement of claim 7 wherein said probe head is coupled to said socket via a conductive solder.

9. The arrangement of claim 8 wherein a contact rode is inserted into said socket, wherein said contact rod is configured to at least receive and relay measurement data obtained from said probe head.

10. The arrangement of claim 1 wherein a contact rod is bonded to said probe head, wherein said contact rod is configured to at least receive and relay measurement data obtained from said probe head.

11. The arrangement of claim 1 wherein said upper electrode is configured to include

a plasma-facing layer, wherein said plasma-facing layer is made of silicon, and

a set of upper layers, wherein said set of upper layers is bonded to said plasma-facing layer, said set of upper layers being made of an electrically and thermally conductive material.

12. The arrangement of claim 11 wherein said set of upper layers is made from aluminum.

13. The arrangement of claim 11 wherein said set of upper layers is made from graphite.

14. The arrangement of claim 11 wherein said upper electrode includes a sleeve, wherein said sleeve includes an internally threaded portion and an ear portion,

15. The arrangement of claim 14 wherein said sleeve is made from aluminum.

16. The arrangement of claim 14 wherein said internally threaded portion is mated with a threaded retainer ring, thereby compressing said o-ring and forcing said flange portion of said probe head downward against said upper surface of said upper electrode.

17. The arrangement of claim 16 wherein said threaded retainer ring includes an inner thru-hole with a larger diameter than a diameter of a socket, wherein said socket is in electrical contact with said probe head.

18. The arrangement of claim 17 wherein a thermal contact ring is disposed between an upper-facing surface of said flange portion and a lower surface of said threaded retainer ring, wherein said thermal contact ring electrically insulates said probe head from said threaded retainer ring.

19. The arrangement of claim 17 wherein said thermal contact ring is made from a silicon polymer.

20. The arrangement of claim 11 wherein said set of upper layers of said upper electrode includes an internally threaded portion, wherein said internally threaded portion is mated with a threaded retainer ring, thereby compressing said o-ring and forcing said flange portion of said probe head downward against said upper surface of said upper electrode.