PLASMA PROCESSING APPARATUS

• US 20080236749A1
• Filed: 03/27/2008
• Published: 10/02/2008
• Est. Priority Date: 03/28/2007
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Matsumoto, Naoki, Ito, Toru, KOSHIMIZU, Chishio, Tanaka, Satoshi
• Granted Patent: US 8,298,371 B2
• Time in Patent Office: Days
• US Class Current: 156/345.33
• CPC Class Codes: H01J 2237/21 Focus adjustment lenses H01J2237/10
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/21 Means for adjusting the focus adjusting the focus while observing the image by photographic or optical means H01J37/22; means for observing the object or the point of impact on the object in tubes for the localised treatment of materials H01J37/3005
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/32155 Frequency modulation
• CPC Class Codes: H01J 37/32165 Plural frequencies
• CPC Class Codes: H01J 37/32348 Dielectric barrier discharge
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32467 Material
• CPC Class Codes: H01J 37/32642 Focus rings

Abstract

A plasma processing apparatus includes a processing chamber, a first electrode and a second electrode disposed to face each other, a high frequency power supply unit for applying a high frequency power to either the first electrode or the second electrode, a processing gas supply unit for supplying a processing gas to a processing space, and a main dielectric member provided at a substrate mounting portion on a main surface of the first electrode. A focus ring is attached to the first electrode to cover a peripheral portion of the main surface of the first electrode and a peripheral dielectric member is provided in a peripheral portion on the main surface of the first electrode so that an electrostatic capacitance per unit area applied between the first electrode and the focus ring is smaller than that applied between the first electrode and the substrate by the main dielectric member.

Claims

1. A plasma processing apparatus comprising:

an evacuable processing chamber;

a first electrode for supporting a target substrate in the processing chamber;

a second electrode disposed to face the first electrode;

a first high frequency power supply unit for applying a first high frequency power having a first frequency to either the first electrode or the second electrode;

a processing gas supply unit for supplying a processing gas to a processing space formed between the first electrode and the second electrode;

a main dielectric member provided at a substrate mounting portion on a main surface of the first electrode;

a focus ring attached to the first electrode to cover a peripheral portion of the main surface of the first electrode positioned in an outer side of the substrate mounting portion; and

a peripheral dielectric member provided in the peripheral portion of the main surface of the first electrode so that an electrostatic capacitance per unit area applied between the first electrode and the focus ring is smaller than an electrostatic capacitance per unit area applied between the first electrode and the substrate by the main dielectric member.

2. The plasma processing apparatus of claim 1, wherein a first conductor is provided in the main dielectric member, and a DC voltage for generating an electrostatic attraction force to the substrate is applied to the first conductor.

3. The plasma processing apparatus of claim 2, wherein a first thermally conductive gas supply unit for supplying a thermally conductive inert gas is provided between the main dielectric member and the substrate.

4. The plasma processing apparatus of claim 1, wherein a second conductor is provided in the peripheral dielectric member, and a DC voltage for generating an electrostatic attraction force to the focus ring is applied to the second conductor.

5. The plasma processing apparatus of claim 4, wherein a second thermally conductive gas supply unit for supplying a thermally conductive inert gas is provided between the peripheral dielectric member and the focus ring.

6. The plasma processing apparatus of claim 1, wherein the peripheral dielectric member is formed in a hollow shape and has therein a fluid dielectric member of which volume is variable.

7. The plasma processing apparatus of claim 1, wherein the peripheral dielectric member is made of a same material forming the main dielectric member.

8. The plasma processing apparatus of claim 1, wherein the peripheral dielectric member has a thickness greater than the thickness of the main dielectric member.

9. The plasma processing apparatus of claim 1, wherein the peripheral dielectric member is integratedly formed with the main dielectric member.

10. The plasma processing apparatus of claim 1, wherein the focus ring comprises a first ring-shaped member provided near an outer edge of the main dielectric member and a second ring-shaped member disposed near an outer peripheral surface of the first ring-shaped member.

11. The plasma processing apparatus of claim 10, wherein the first ring-shaped member is disposed so that a gap formed between an outer edge of the substrate supported on the main dielectric member and an inner peripheral surface of the second ring-shaped member is positioned above the first ring-shaped member.

12. The plasma processing apparatus of claim 10, wherein a conductor for generating an electrostatic attraction force to the focus ring is provided in the peripheral dielectric member to face the second-ring shaped member.

13. The plasma processing apparatus of claim 1, further comprising a second high frequency power supply unit for applying to the first electrode a second high frequency power having a second frequency lower than the first frequency.

14. A plasma processing apparatus comprising:

an evacuable processing chamber;

a first electrode for supporting a target substrate in the processing chamber;

a second electrode disposed to face the first electrode;

a first high frequency power supply unit for applying a first high frequency power having a first frequency to either the first electrode or the second electrode;

a processing gas supply unit for supplying a processing gas to a processing space formed between the first electrode and the second electrode;

a main dielectric member provided at a substrate mounting portion on a main surface of the first electrode;

a focus ring attached to the first electrode to cover a peripheral portion of the main surface of the first electrode positioned in an outer side of the substrate mounting portion;

a peripheral insulating member provided in a peripheral portion on the main surface of the first electrode contacted with the focus ring; and

an electrostatic capacitance varying unit for varying an electrostatic capacitance of the peripheral insulating portion.

15. The plasma processing apparatus of claim 14, wherein the electrostatic capacitance varying unit has a variable capacitor.

16. A plasma processing apparatus comprising:

an evacuable processing chamber;

a main lower electrode for supporting a target substrate in the processing chamber;

a peripheral lower electrode extending in a ring shape to surround an outer periphery of the main lower electrode, the peripheral lower electrode being electrically insulated from the main lower electrode;

a focus ring attached to cover a top surface of the peripheral lower electrode;

an upper electrode disposed above the main lower electrode and the peripheral lower electrode to face thereto;

a processing gas supply unit for supplying a processing gas to a processing space formed between the main lower electrode and the upper electrode;

a first high frequency power supply unit for applying a first high frequency power having a first frequency to the main lower electrode and the peripheral lower electrode; and

a second high frequency power supply unit for applying a second high frequency power having a second frequency lower than the first frequency to the main lower electrode.

17. The plasma processing apparatus of claim 16, further comprising a main dielectric member provided on the top surface of the main lower electrode and a peripheral dielectric member provided on the top surface of the peripheral lower electrode.