Bypass capacitors for high voltage bias power in the mid frequency RF range

• US 9,083,182 B2
• Filed: 11/21/2012
• Issued: 07/14/2015
• Est. Priority Date: 11/21/2011
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Sato, Arthur
• Primary Examiner(s): Nguyen, Danny
• Application Number:
  US13/684,065
• Publication Number:
  US 20130128397A1
• Time in Patent Office: 965 Days
• Field of Search: 361/234, 361/230
• US Class Current: 1/1
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32944 Arc detection
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/6831 using electrostatic chucks
• CPC Class Codes: H01L 21/6833 Details of electrostatic chucks
• CPC Class Codes: H01L 21/68742 characterised by a lifting arrangement, e.g. lift pins
• CPC Class Codes: H02H 3/46 responsive to frequency deviations
• CPC Class Codes: H05F 3/00 Carrying-off electrostatic charges from shoes A43B7/36; from living beings A61N1/14; from tyres B60C19/08; from vehicles B60R16/06; from aircraft B64D45/02; from large containers B65D90/46

Abstract

A system for decoupling arcing RF signals in a plasma chamber including a top electrode, an electrostatic chuck for supporting a semiconductor wafer, and a capacitor coupled between the at least one of a plurality of clamping electrodes in the surface of the electrostatic chuck and a baseplate of the electrostatic chuck, the capacitor having a capacitance of greater than about 19 nanofarads, the capacitor disposed within an interior volume of the electrostatic chuck. A method of decoupling arcing RF signals in a plasma chamber is also disclosed.

Claims

1. A system for decoupling arcing RF signals in a plasma chamber comprising:

a plasma chamber including;

a top electrode;

an electrostatic chuck for supporting a semiconductor wafer; and

a capacitor coupled between the at least one of a plurality of clamping electrodes in the surface of the electrostatic chuck and a baseplate of the electrostatic chuck, the capacitor having a capacitance of greater than about 19 nanofarads, the capacitor disposed within an interior volume of the electrostatic chuck;

a plurality of lift pins supported in a corresponding plurality of lift pin holes in the surface of the electrostatic chuck, wherein each one of the plurality of lift pins has a clearance of less than about 0.011 inches (0.25 mm) between a corresponding side in a corresponding one of a plurality of lift pin holes in the surface of the electrostatic chuck.

3. The system of claim 1, wherein at least one of the plurality of lift pins is a round-tip lift pin.

4. The system of claim 1, wherein at least one of the plurality of lift pins is a flat tip lift pin.

5. The system of claim 1, wherein at least one of the plurality of lift pins is a broadened flat tip lift pin.

6. The system of claim 1, wherein the capacitor has a capacitance of between about 19 nanofarads and about 43 nanofarads.

13. The system of claim 1, wherein the RF signals provided to the plasma chamber are at a frequency of about 400 KHz.

2. A system for decoupling arcing RF signals in a plasma chamber comprising:

a plasma chamber including;

a top electrode;

an electrostatic chuck for supporting a semiconductor wafer; and

a capacitor coupled between the at least one of a plurality of clamping electrodes in the surface of the electrostatic chuck and a baseplate of the electrostatic chuck, the capacitor having a capacitance of greater than about 19 nanofarads, the capacitor disposed within an interior volume of the electrostatic chuck;

a plurality of lift pins supported in a corresponding plurality of lift pin holes in the surface of the electrostatic chuck, wherein each one of the plurality of lift pins has a clearance of less than about 0.005 inches (0.12 mm) between a corresponding side in a corresponding one of a plurality of lift pin holes in the surface of the electrostatic chuck.

14. The system of claim 2, wherein the RF signals provided to the plasma chamber are at a frequency of about 400 KHz.

7. A method of decoupling arcing RF signals in a plasma chamber comprising:

generating a plasma in the region between a top electrode and a top surface of an electrostatic chuck in a plasma chamber including applying one or more RF signals to one or both of the top electrode and the electrostatic chuck, wherein a semiconductor wafer is supported on the top surface of an electrostatic chuck; and

coupling a portion of the one or more RF signals through a capacitor coupled between a plurality of clamping electrodes in the top surface of the electrostatic chuck and a baseplate of the electrostatic chuck, the capacitor having a capacitance of at least 19 nanofarads, the capacitor disposed within an interior volume of the electrostatic chuck, and

providing a plurality of lift pins in a corresponding plurality of lift pin holes in the top surface of the electrostatic chuck, wherein each one of the plurality of lift pins has a clearance of less than about 0.011 inches (0.25 mm) between a corresponding side in a corresponding one of a plurality of lift pin holes in the top surface of the electrostatic chuck.

8. The method of claim 7, wherein the capacitor has a capacitance of between about 19 nanofarads and about 43 nanofarads.

9. The method of claim 7, wherein at least one of the plurality of lift pins is a round-tip lift pin.

10. The method of claim 7, wherein at least one of the plurality of lift pins is a flat tip lift pin.

11. The method of claim 7, wherein at least one of the plurality of lift pins is a broadened flat tip lift pin.

15. The method of claim 7, wherein the RF signals provided to the plasma chamber are at a frequency of about 400 KHz.

12. A system for decoupling arcing RF signals in a plasma chamber comprising:

a plasma chamber including;

a top electrode;

an electrostatic chuck for supporting a semiconductor wafer;

a capacitor coupled between the at least one of a plurality of clamping electrodes in the surface of the electrostatic chuck and a baseplate of the electrostatic chuck, the capacitor having a capacitance of between about 19 nanofarads and about 43 nanofarads, the capacitor disposed within an interior volume of the electrostatic chuck; and

a plurality of lift pins supported in a corresponding plurality of lift pin holes in the surface of the electrostatic chuck, wherein each one of the plurality of lift pins has a clearance of less than about 0.005 inches (0.12 mm) between a corresponding side in a corresponding one of a plurality of lift pin holes in the surface of the electrostatic chuck.

16. The method of claim 12, wherein the RF signals provided to the plasma chamber are at a frequency of about 400 KHz.