Plasma processing apparatus

• US 20030164142A1
• Filed: 09/23/2002
• Published: 09/04/2003
• Est. Priority Date: 01/25/2001
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Koshimizu, Chischio
• Granted Patent: US 6,949,165 B2
• Time in Patent Office: Days
• US Class Current: 118/409
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/32642 Focus rings
• CPC Class Codes: H01J 37/32706 Polarising the substrate

Abstract

An electrical connection means 45 guides a DC voltage, which is generated in an ion sheath when a plasma is excited, to a first electrode 31 where a substrate W is placed. Hence, the DC voltage is applied to both the upper and lower surfaces of the substrate W, so the two surfaces of the substrate have the same potential. As a result, element breakdown, which occurs when a large potential difference occurs between the two surfaces of the substrate W, can be prevented.

Claims

1. A plasma processing apparatus characterized by comprising

a vessel where a predetermined vacuum degree is to be maintained,

a plasma source which generates a plasma in said vessel,

a first electrode which is arranged in said vessel and on which a substrate to be processed by the plasma is placed,

a focus ring arranged on a periphery of said first electrode, and

electrical connection means for guiding to said first electrode a DC voltage which is generated in an ion sheath when the plasma is generated

2. A plasma processing apparatus according to claim 1, characterized in that

the apparatus further comprises a second electrode arranged in said vessel to oppose said first electrode, and

said plasma source is formed of, of said first and second electrodes, that electrode to which a first power for generating the plasma is supplied.

3. A plasma processing apparatus according to claim 1, characterized in that said electrical connection means is formed of a conductive member having one end which is exposed to a space where the plasma is present when the plasma is generated, and the other end which is electrically connected to said first electrode.

4. A plasma processing apparatus according to claim 3, characterized in that said focus ring has a through hole through which the space and said first electrode communicate with each other, and said conductive member is inserted in the through hole.

5. A plasma processing apparatus according to claim 3, characterized in that

the apparatus further comprises an insulator extending to a side surface of said first electrode and made of an insulating material,

said insulator having a through hole through which the space and said first electrode communicate with each other, and said conductive member being inserted in the through hole.

6. A plasma processing apparatus according to claim 4, characterized in that one end of said conductive member is made of a material containing the same material as that of the substrate as a major component.

7. A plasma processing apparatus according to claim 5, characterized in that one end of said conductive member is made of a material containing the same material as that of the substrate as a major component.

8. A plasma processing apparatus according to claim 2, characterized in that said electrical connection means is formed of a through hole formed in said focus ring to extend between a first electrode-side surface and a second electrode-side surface thereof, and that region on said first electrode which faces the through hole is conductive.

9. A plasma processing apparatus according to claim 8, characterized in that said region on said first electrode which faces the through hole formed in said focus ring is made of a material containing the same material as that contained in the substrate as a major component.

10. A plasma processing apparatus according to claim 1, characterized in that

said focus ring is made of a conductor, and

said electrical connection means is formed by electrical connection of said focus ring and first electrode.

11. A plasma processing apparatus according to claim 10, characterized by having a filter connected between said focus ring and said first electrode and serving to adjust a transmission amount of the DC voltage.

12. A plasma processing apparatus according to claim 11, characterized in that

the apparatus further comprises a power supply for supplying a second power to said first electrode, and

said filter adjusts a passing phase of the second power so a phase at the second power of the substrate and that at said focus ring coincide with each other.