Auto-calibration to a station of a process module that spins a wafer

Patent metadata

Field	Value
Publication number	US-11742229-B2
Application number	US-202117553658-A
Country	US
Kind code	B2
Filing date	Dec 16, 2021
Priority date	Dec 6, 2017
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

A method for calibration including determining a temperature induced offset in a pedestal of a process module under a temperature condition for a process. The method includes delivering a wafer to the pedestal of the process module by a robot, and detecting an entry offset. The method includes rotating the wafer over the pedestal by an angle. The method includes removing the wafer from the pedestal by the robot and measuring an exit offset. The method includes determining a magnitude and direction of the temperature induced offset using the entry offset and exit offset.

First claim

What is claimed is:

1. A system for processing a wafer, comprising:
a process module including a rotation device having a rotation axis;
a pedestal within the process module configured for supporting a process wafer;
a transfer robot configured for transferring the process wafer to and from the process module; and
a measurement system fixed within a reference coordinate system, wherein the measurement system is configured to determine an alignment offset of the process wafer when transferring the process wafer to the pedestal,
wherein the transfer robot is configured to apply an alignment correction corresponding to the alignment offset,
wherein the transfer robot is configured to apply a condition correction of the rotation axis of the rotation device of the process module, wherein the condition correction is determined based on measuring a calibration wafer by the measurement system during entry into the process module and during exit from the process module after rotation,
wherein the process module is under a process condition.

2. The system of claim 1 ,
wherein the measurement system is configured to determine an entry offset of the calibration wafer within the reference coordinate system when transferring the calibration wafer to the pedestal using the transfer robot when the process module is under the process condition,
wherein the measurement system is configured to determine an exit offset of the calibration wafer when transferring the calibration wafer from the process module using the transfer robot after the calibration wafer has been rotated within the process module by the rotation device,
wherein the entry offset and exit offset are based on an initial calibrated location of a center of the pedestal,
wherein a condition induced offset of the rotation axis is based on the entry offset and the exit offset,
wherein the condition correction is based on the condition induced offset.

3. The system of claim 2 ,
wherein the transfer robot is taught the center of the pedestal to determine the initial calibrated location of the rotation axis of the rotation device, wherein the initial calibrated location corresponds to the center of the pedestal and the rotation axis; and
wherein the transfer robot is used to transfer the calibration wafer from the initial calibrated location pedestal to a calibrated reference location.

4. The system of claim 1 ,
wherein the reference coordinate system is based on an initial calibrated location of a center of the pedestal.

5. The system of claim 1 ,
wherein the alignment offset is measured from a calibrated reference location that is calibrated to place the calibration wafer directly at a center of the pedestal.

6. The system of claim 5 ,
wherein the calibrated reference location is outside of the process module.

7. The system of claim 1 ,
wherein the process condition includes at least one of a temperature level or a vacuum level.

8. The system of claim 1 , wherein the rotation device is located on an end-effector.

9. The method of claim 1 , wherein the rotation device is a lift pad configured to separate from the pedestal.

10. A method, comprising:
determining an alignment offset of a process wafer when transferring the process wafer to a pedestal in a process module;
applying an alignment correction corresponding to the alignment offset; and
applying a condition correction of a rotation axis of a rotation device of the process module, wherein the condition correction is determined based on measuring a calibration wafer by a measurement system during entry into the process module and during exit from the process module after rotation,
wherein the process module is under a process condition.

11. The method of claim 10 , further comprising:
determining an entry offset of the calibration wafer within a reference coordinate system associated with the process module when transferring the calibration wafer to the pedestal of the process module, the entry offset being based on an initial calibrated location of a center of the pedestal;
rotating the calibration wafer within the process module using the rotation device;
determining an exit offset of the calibration wafer within the reference coordinate system when transferring the calibration wafer from the pedestal of the process module, the exit offset being based on the initial calibrated location of the center of the pedestal; and
determining a condition induced offset of the rotation axis of the rotation device using the entry offset and the exit offset; and
determining the condition correction based on the condition induced offset,
wherein the process module is under no condition when performing the determining the entry offset, and the rotating the calibration wafer, and the determining the exit offset.

12. The method of claim 11 ,
wherein the reference coordinate system is based on the initial calibrated location of the center of the pedestal.

13. The method of claim 10 ,
wherein the alignment offset is measured from a calibrated reference location that is calibrated to place the calibration wafer directly at a center of the pedestal.

14. The method of claim 13 ,
wherein the calibrated reference location is outside of the process module.

15. The method of claim 13 , further comprising:
teaching a transfer robot to the center of the pedestal to determine an initial calibrated location of the rotation axis of the rotation device, wherein the initial calibrated location corresponds to the center of the pedestal and the rotation axis; and
determining the calibrated reference location by using the transfer robot to transfer the calibration wafer from the pedestal at the initial calibrated location to the calibrated reference location.

16. The method of claim 15 ,
wherein the transfer robot is configured for applying the condition correction when transferring a plurality of wafers to and from the process module.

17. The method of claim 10 ,
wherein the process condition includes at least one of a temperature level or a vacuum level.

18. The method of claim 10 , wherein the rotation device is located on an end-effector.

19. The method of claim 10 , wherein the rotation device is a lift pad configured to separate from the pedestal.

20. The method of claim 10 , wherein the rotation device is the pedestal.

Assignees

• Lam Res Corp

Inventors

• Hiester Jacob L
• Blank Richard
• Thaulad Peter
• Konkola Paul

Classifications

• H10P72/72

  using electrostatic chucks · CPC title

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• H10P72/7621

  characterised by supporting two or more semiconductor substrates · CPC title

• H10P72/7618

  characterised by a movable susceptor, stage or support, others than those only rotating on their own vertical axis, e.g. susceptors on a rotating carrousel · CPC title

• H10P72/7612

  characterised by lifting arrangements, e.g. lift pins · CPC title