Wafer bias drive for plasma source

• US 20040018127A1
• Filed: 06/11/2003
• Published: 01/29/2004
• Est. Priority Date: 12/19/2000
• Status: Abandoned Application

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Long, Maolin, Parsons, Richard, Johnson, Wayne L.
• Application Number:
  US10/458,801
• Publication Number:
  US 20040018127A1
• Time in Patent Office: Days
• US Class Current: 422/186.04
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/32532 Electrodes
• CPC Class Codes: H01J 37/32706 Polarising the substrate
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/6838 with gripping and holding devices using a vacuum; Bernoulli devices

Abstract

A segmented chuck provides uniform processing of a workpiece (e.g., a wafer) with a plasma in a process chamber. The segmented chuck includes a segmented electrode having a plurality of sub-electrodes where the sub-electrodes are electrically isolated from one another by insulating connections and the segmented electrode defines a process surface that is adapted to receive the workpiece. The segmented chuck also includes a plurality of RF drivers for driving the sub-electrodes with RF biases, where the RF biases couple the workpiece with the plasma in the process chamber. By allowing the workpiece to be placed on the chuck, the coupling between the plasma and the workpiece is enhanced. By allowing the sub-electrodes to be independently driven by RF drivers, more uniform processing can be achieved with larger workpieces.

Claims

1. A segmented chuck for processing of a workpiece with a plasma in a process chamber, comprising:

a segmented electrode having a plurality of sub-electrodes, the sub-electrodes being separated from one another, and the segmented electrode defining a process surface that is adapted to receive the workpiece; and

a plurality of RF drivers for driving the sub-electrodes with RF biases, wherein the RF biases couple the workpiece with the plasma in the process chamber.

2. A segmented chuck as claimed in claim 1, wherein the process surface is substantially planar.

3. A segmented chuck as claimed in claim 2, further comprising:

a lift-pin assembly that is integrated with the process surface, wherein the lift-pin assembly operates to load and to unload the workpiece with respect to the process surface.

4. A segmented chuck as claimed in claim 1, wherein each sub-electrode is uniquely identified with a corresponding RF driver.

5. A segmented chuck as claimed in claim 4, further comprising a plurality of control units, the control units operating to determine RF driver inputs, the control units being adapted to transmit the RF driver inputs to the RF drivers, wherein the RF drivers control the RF biases based on the RF driver inputs.

6. A segmented chuck as claimed in claim 1, further comprising a chuck enclosure that contains the segmented electrode and the RF drivers.

7. A segmented chuck as claimed in claim 1, wherein each RF driver comprises a match network and a RF bias power supply.

8. A segmented chuck as claimed in claim 7, further comprising a chuck enclosure that contains the segmented electrode and at least one match network.

9. A segmented chuck as claimed in claim 7, wherein each RF bias power supply comprises a phase shifter, a circulator, amplifier, and a phase shifter.

10. A segmented chuck as claimed in claim 1, further comprising:

a chuck enclosure that contains the segmented electrode; and

a plurality of RF transmission lines that connect the RF drivers to the segmented electrode, wherein the RF drivers and the control units are exterior to the chuck enclosure.

11. A system for plasma processing of a workpiece, comprising:

a process chamber;

a plasma source, the plasma source operating to generate a plasma in the process chamber;

a segmented chuck having a segmented electrode and a plurality of RF drivers, the segmented electrode having a plurality of sub-electrodes, the sub-electrodes being separated from one another, the segmented electrode defining a process surface that is adapted to receive the workpiece, and the RF drivers operating to drive the sub-electrodes with RF biases that couple the workpiece with the plasma;

a sensor, the sensor having visual access to the process surface through an optical interface in the process chamber, and the sensor operating to determine process data; and

a control system, the control system operating to generate RF driver inputs from the process data, the control system being adapted to receive the process data from the sensor and to transmit the RF driver inputs to the RF drivers, wherein the RF drivers control the RF biases in response to the RF driver inputs.

12. A system as claimed in claim 11, wherein the process surface is substantially planar.

13. A system as claimed in claim 12, further comprising:

a lift-pin assembly that is integrated with the process surface, wherein the lift-pin assembly operates to load and to unload the workpiece with respect to the process surface.

14. A system as claimed in claim 11, wherein each sub-electrode is uniquely identified with a corresponding RF driver.

15. A system as claimed in claim 14, further comprising a plurality of control units, the control units operating to determine RF driver inputs, the control units being adapted to transmit the RF driver inputs to the RF drivers, wherein the RF drivers control the RF biases based on the RF driver inputs.

16. A system as claimed in claim 11, further comprising a chuck enclosure that contains the segmented electrode and the RF drivers.

17. A system as claimed in claim 11, further comprising:

a chuck enclosure that contains the segmented electrode; and

a plurality of RF transmission lines that connect the RF drivers to the segmented electrode, wherein the RF drivers and the control units are exterior to the process chamber.

18. A method for plasma processing of a workpiece, comprising:

loading the workpiece onto a process surface in a plasma chamber, the process surface being defined by a segmented electrode, the segmented electrode including a plurality of sub-electrodes that are separated from one another;

generating a plasma in the process chamber;

coupling the workpiece with the plasma for plasma processing by using RF drivers to generate RF biases at the sub-electrodes, the RF drivers and the segmented electrodes being included in a segmented chuck;

determining process data from the plasma processing;

generating RF driver inputs from the process data;

adjusting the RF biases of the RF drivers based on the RF driver inputs; and

unloading the workpiece from the process surface after plasma processing.

19. A method as claimed in claim 18, wherein each sub-electrode is uniquely identified with a corresponding RF driver.

20. A method as claimed in claim 19, wherein the act of generating RF driver inputs from process data includes determining a process uniformity condition from the process data.

21. A method as claimed in claim 19, wherein the act of generating RF driver inputs from process data includes determining a process endpoint condition from the process data.