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

Patent metadata

Field	Value
Publication number	US-10651065-B2
Application number	US-201816000734-A
Country	US
Kind code	B2
Filing date	Jun 5, 2018
Priority date	Dec 6, 2017
Publication date	May 12, 2020
Grant date	May 12, 2020

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 method for determining a temperature induced offset in a pedestal of a process module under a temperature condition for a process, comprising:
delivering a wafer to the pedestal of the process module by a robot, and detecting an entry offset;
rotating the wafer over the pedestal by an angle;
removing the wafer from the pedestal by the robot and measuring an exit offset;
determining a magnitude and direction of the temperature induced offset using the entry offset and the exit offset;
defining a calibrated reference measurement within a reference coordinate system based on an initial calibrated location of the pedestal within the process module, wherein the entry offset is measured from the calibrated reference measurement, wherein the exit offset is measured from the calibrated reference measurement; and
determining a temperature correction of a center of the pedestal based on the temperature induced offset corresponding to an offset of the center of the pedestal from the initial calibrated location when the process module is under the temperature condition.

2. The method of claim 1 , further comprising:
wherein the detecting an entry offset includes determining a first measurement of the wafer within the reference coordinate system using a measurement device that is fixed within the reference coordinate system; and
wherein the measuring an exit offset includes determining a second measurement of the wafer within the reference coordinate system using the measurement device.

3. The method of claim 1 , further comprising:
when no condition is applied to the process module, calibrating the robot to the initial calibrated location corresponding to the center of the pedestal, the reference coordinate system being based on the initial calibrated location;
placing a calibration wafer centered to the pedestal;
removing the calibration wafer from the pedestal using the robot; and
defining the calibrated reference measurement of the calibration wafer within the reference coordinate system using a measurement device that is fixed within the reference coordinate system, the calibrated reference measurement being aligned with the initial calibrated location.

4. The method of claim 1 , wherein the determining a temperature correction includes:
determining a difference vector between the entry offset and the exit offset; and
halving a magnitude of the difference vector to determine the temperature induced offset of the center of the pedestal from the initial calibrated location.

5. The method of claim 1 , wherein the rotating the wafer includes:
placing the wafer on a lift pad configured to separate from the pedestal and rotate with respect to the pedestal;
separating the lift pad from the pedestal along a rotation axis; and
rotating the lift pad relative to the pedestal between at least a first angular orientation and a second angular orientation defining the angle.

6. A method for calibration, comprising:
establishing a reference coordinate system based on an initial calibrated location of a rotation axis of a rotation device within a process module;
applying a condition to the process module;
picking up a calibration wafer from an inbound load lock using a transfer module (TM) robot configured to transfer the calibration wafer to the process module;
determining a first measurement of the calibration wafer within the reference coordinate system using a measurement device when transferring the calibration wafer to the process module, the measurement device fixed within the reference coordinate system;
handing off the calibration wafer to the process module;
interfacing the calibration wafer with the rotation device;
rotating the calibration wafer by an angle using the rotation device;
removing the calibration wafer from the process module using the TM robot;
determining a second measurement of the calibration wafer within the reference coordinate system using the measurement device when transferring the calibration wafer to an outbound load lock; and
determining a condition correction of the rotation axis based on the first measurement and the second measurement, the condition correction corresponding to an offset of the rotation axis from the initial calibrated location when the process module is under the condition.

7. The method of claim 6 , wherein the determining a condition correction includes:
determining a difference vector between the first measurement and the second measurement; and
halving a magnitude of the difference vector to determine the offset of the rotation axis from the initial calibrated location.

8. The method of claim 6 , wherein the applying a condition includes performing at least one of the following operations:
bringing the process module to a process temperature; or
applying a vacuum to the process module.

9. The method of claim 6 , wherein the establishing a reference coordinate system includes:
when no condition is applied to the process module, calibrating the TM robot to the initial calibrated location;
placing the calibration wafer within the rotation device and centered to the rotation axis;
removing the calibration wafer from the process module using the TM robot; and
establishing a calibrated reference measurement of the calibration wafer within the reference coordinate system using the measurement device, the calibrated reference measurement being aligned with the initial calibrated location of the rotation axis.

10. The method of claim 6 , wherein the rotating the calibration wafer by an angle includes:
placing the calibration wafer on a lift pad of the rotation device, the rotation device interfacing with a pedestal having a pedestal top surface extending from a central axis of the pedestal, the lift pad configured to rest upon the pedestal top surface or be separated from the pedestal top surface;
separating the lift pad from the pedestal top surface along the central axis; and
rotating the lift pad relative to the pedestal top surface between at least a first angular orientation and a second angular orientation defining the angle.

11. The method of claim 10 , wherein the angle ranges from greater than 0 degrees to less than or equal to 180 degrees.

12. The method of claim 10 , wherein a diameter of the lift pad is approximately sized to a wafer diameter.

13. The method of claim 10 , wherein a diameter of the lift pad is smaller than a wafer diameter.

14. The method of claim 6 , wherein the rotating the calibration wafer by the angle includes:
picking up the calibration wafer from a first station in the process module using an end effector of a spindle robot, the spindle robot configured for transferring wafers between stations in the process module, wherein the end effector is configured for rotating the calibration wafer; and
placing the calibration wafer after rotation on the first station for removal from the process module.

15. A method for calibration, comprising:
establishing a reference coordinate system based on an initial calibrated location of a rotation axis of a rotation device within a process module;
establishing a calibrated reference measurement of a calibration wafer within the reference coordinate system using a measurement device fixed within the reference coordinate system when transferring the calibration wafer from the process module from the initial calibrated location using a transfer module (TM) robot, the calibration wafer placed to be centered about the rotation axis such that the calibrated reference measurement is aligned with the initial calibrated location of the rotation ax

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