ELECTRODE HAVING GAS DISCHARGE FUNCTION AND PLASMA PROCESSING APPARATUS

• US 20120247673A1
• Filed: 03/30/2012
• Published: 10/04/2012
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: HAYASHI, Daisuke, ISHIDA, Toshifumi, AMIKURA, Norihiko
• Granted Patent: US 9,082,593 B2
• Time in Patent Office: Days
• US Class Current: 156/345.33
• CPC Class Codes: C23C 16/455 characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
• CPC Class Codes: C23C 16/45563 Gas nozzles
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45576 Coaxial inlets for each gas
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: C23C 16/503 using dc or ac discharges
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: C23C 16/509 using internal electrodes
• CPC Class Codes: C23F 1/12 Gaseous compositions
• CPC Class Codes: H01J 1/00 Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps details of electron-optical arrangements or of ion traps H01J3/00
• CPC Class Codes: H01J 1/02 Main electrodes
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32532 Electrodes

Abstract

An electrode having a gas discharge function, where the degree of freedom related to a maximum gas flow rate is abundant, an electrode cover member may be thinned, and a change of a gas behavior according to time is difficult to be generated in a processing chamber during gas introduction. The electrode includes: a base material having a plurality of gas holes; and an electrode cover member having a plurality of gas holes respectively corresponding to the plurality of gas holes of the base material in a one-to-one manner, fixed to the base material, and disposed facing a processing space in which the object is plasma-processed, wherein a gas hole diameter of the electrode cover member is larger than a gas hole diameter of the base material.

Claims

1. An electrode having a gas discharge function, which is used in a plasma processing apparatus and disposed facing an electrode on which an object is held, the electrode having the gas discharge function comprising:

a base material having a plurality of gas holes; and

an electrode cover member fixed to the base material, disposed facing a processing space in which the object is plasma-processed, and having a plurality of gas holes respectively corresponding to the plurality of gas holes of the base material in a one-to-one manner,

wherein a gas hole diameter of the electrode cover member is larger than a gas hole diameter of the base material.

2. The electrode having the gas discharge function of claim 1, wherein the gas hole diameter of the electrode cover member is more than or equal to 1.5 times and less than or equal to 3 times of the gas hole diameter of the base material.

3. The electrode having the gas discharge function of claim 2, wherein the gas hole diameter of the electrode cover member is more than or equal to 1 mm and less than or equal to 2 mm.

4. The electrode having the gas discharge function of claim 1, wherein a clearance portion having a concave shape and larger than the gas hole diameter of the electrode cover member is formed on at least one of a surface, of the base material, attached to the electrode cover member and a surface, of the electrode cover member, attached to the base material.

5. The electrode having the gas discharge function of claim 4, wherein a depth of an outer circumference of the clearance portion having the concave shape is shallower than a depth of an inner side of the clearance portion having the concave shape.

6. The electrode having the gas discharge function of claim 1, wherein a gas hole of the base material and a gas hole of the electrode cover member corresponding to the gas hole of the base material are misaligned so as not to overlap each other.

14. The electrode having the gas discharge function of claim 4, wherein an abrasion tolerant coating process is performed on a portion, of the clearance portion having the concave shape, facing the electrode cover member.

15. The electrode having the gas discharge function of claim 14, wherein a coating film formed by the abrasion tolerant coating process comprises at least any one of an yttrium oxide sprayed coating film, an alumina sprayed coating film, an yttrium fluoride sprayed coating film, and an anodized coating film.

16. The electrode having the gas discharge function of claim 4, wherein a chamfered portion having a tapered shape is formed at a portion, of a gas hole of the electrode cover member, facing the base material,

wherein the chamfered portion has a hole diameter larger than the gas hole diameter of the electrode cover member and smaller than a hole diameter of the clearance portion having the concave shape.

17. The electrode having the gas discharge function of claim 1, wherein the electrode cover member is replaceable.

18. The electrode having the gas discharge function of claim 17, wherein the replaceable electrode cover member is formed by a brittle material.

19. The electrode having the gas discharge function of claim 18, wherein the brittle material comprises at least any one of quartz, alumina, an yttrium sintered body, aluminum nitride, silicon nitride, silicon carbide, silicon, and calcium fluoride.

20. The electrode having the gas discharge function of claim 1, wherein a thickness of the electrode cover member is more than or equal to 3 mm and less than or equal to 15 mm.

21. The electrode having the gas discharge function of claim 1, wherein a direction of a gas hole of the electrode cover member is tilted in a middle of the electrode cover member.

22. The electrode having the gas discharge function of claim 21, wherein a direction of a gas hole of the electrode cover member at the processing space is perpendicular to the processing space.

23. The electrode having the gas discharge function of claim 21, wherein a gas hole of the base material is hidden by using a side surface of the tilted gas hole of the electrode cover member such that the gas hole of the base material is not seen from the processing space.

24. A plasma processing apparatus comprising:

a processing chamber in which a process is performed on an object;

a holding stage formed in the processing chamber, on which the object is held, and serving as an electrode; and

an electrode having a gas discharge function, formed in the processing chamber, and disposed facing the holding stage,

wherein the electrode having the gas discharge function of claim 1 is used as the electrode having the gas discharge function.

25. The plasma processing apparatus of claim 24, wherein the plasma processing apparatus performs a purge process during the process.

26. The plasma processing apparatus of claim 24, wherein the plasma processing apparatus performs cleaning inside the processing chamber by using a gas impact force generated by introducing a cleaning gas from the electrode having the gas discharge function.

7. An electrode having a gas discharge function, used in a plasma processing apparatus and disposed facing an electrode on which an object is held, the electrode having the gas discharge function comprising:

a base material having a plurality of gas holes; and

an electrode cover member having a plurality of gas hole groups, fixed to the base material, and disposed facing a processing space in which the object is plasma-processed, wherein each gas hole group of the electrode cover member has a plurality of gas holes, and the plurality of gas holes in one gas hole group of the electrode cover member correspond to one gas hole of the plurality of gas holes of the base material in a many-to-one manner.

8. The electrode having the gas discharge function of claim 7, wherein one gas hole of the base material and a plurality of gas holes included in the gas hole group, of the electrode cover member, corresponding to the one gas hole of the base material are misaligned so as not to overlap each other.

9. The electrode having the gas discharge function of claim 7, wherein a gas hole diameter of the electrode cover member is smaller than or equal to a gas hole diameter of the base material, and

composite conductance obtained by adding conductances of a plurality of gas holes included in the one gas hole group of the electrode cover member is higher than conductance of one gas hole of the base material.

10. The electrode having the gas discharge function of claim 7, wherein a gas hole diameter of the electrode cover member is larger than a gas hole diameter of the base material.

11. The electrode having the gas discharge function of claim 7, wherein a clearance portion having a concave shape, larger than the gas hole diameter of the electrode cover member, and including the gas hole group of the electrode cover member is formed on at least one of a surface, of the base material, attached to the electrode cover member and a surface, of the electrode cover member, attached to the base material.

12. The electrode having the gas discharge function of claim 11, wherein a depth of an outer circumference of the clearance portion having the concave shape is shallower than a depth of an inner side of the clearance portion having the concave shape.

13. The electrode having the gas discharge function of claim 12, wherein a region where a depth of the clearance portion having the concave shape is shallower is outside the gas hole group.