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US-20260130167-A1 - WARPAGE AMOUNT ESTIMATION APPARATUS AND WARPAGE AMOUNT ESTIMATION METHOD

US20260130167A1US 20260130167 A1US20260130167 A1US 20260130167A1US-20260130167-A1

Abstract

A warpage amount estimation apparatus that estimates a warpage amount of a substrate includes a processor and a memory. The processor acquires a captured image of one surface of an estimation target substrate. The processor calculates a rate of change in pixel value relating to a substrate radial direction in the captured image of the one surface of the estimation target substrate. The processor estimates a warpage amount of the estimation target substrate based on a correlation obtained in advance between a rate of change in pixel value relating to the substrate radial direction in a captured image of the one surface of a substrate and a warpage amount of the substrate, and on a calculation result of the rate of change which is calculated.

Inventors

  • Akiko Kiyotomi

Assignees

  • TOKYO ELECTRON LIMITED

Dates

Publication Date
20260507
Application Date
20251230
Priority Date
20201027

Claims (16)

  1. 1 . A warpage amount estimation apparatus for estimating a warpage amount of a substrate, comprising: a processor having a memory, the processor is configured to acquire a captured image of an estimation target substrate; perform a calculation of a rate of change in pixel value continuously changing in a substrate radial direction in the captured image of the estimation target substrate; and perform an estimation of a warpage amount of the estimation target substrate based on a correlation obtained in advance between a rate of change in pixel value continuously changing in the substrate radial direction in a captured image of a substrate, and a warpage amount of the substrate, and on a calculation result of the rate of change which is calculated.
  2. 2 . The warpage amount estimation apparatus according to claim 1 , wherein the processor is further configured to remove a portion within which the rate of change in pixel value exceeds a predetermined threshold from the captured image of the estimation substrate, and perform the calculation based on the captured image of the estimation target substrate from which the portion has been removed.
  3. 3 . The warpage amount estimation apparatus according to claim 2 , wherein the portion is predetermined.
  4. 4 . The warpage amount estimation apparatus according to claim 3 , wherein the processor is further configured to determine the portion in the captured image of the estimation target substrate from the captured image of the estimation target substrate.
  5. 5 . The warpage amount estimation apparatus according to claim 4 , wherein the processor is further configured to determine a portion where a pixel value is not within a predetermined range in the captured image of the estimation target substrate, to be the portion.
  6. 6 . The warpage amount estimation apparatus according to claim 5 , wherein the processor is further configured to determine a portion determined to be a defect in defect inspection based on the captured image of the estimation target substrate, to be the portion.
  7. 7 . The warpage amount estimation apparatus according to claim 1 , wherein the processor is further configured to select a region relating to a substrate circumferential direction to be used for the calculation in the captured image of the estimation target substrate.
  8. 8 . The warpage amount estimation apparatus according to claim 7 , wherein the processor is further configured to select a plurality of regions relating to the substrate circumferential direction to be used for the calculation.
  9. 9 . The warpage amount estimation apparatus according to claim 1 , wherein the processor is further configured to perform the calculation based on a captured image of the estimation target substrate averaged in a circumferential direction of the substrate.
  10. 10 . The warpage amount estimation apparatus according to claim 1 , wherein the processor is further configured to exclude an outlier from pixel values included in the captured image of the estimation target substrate to be used for the calculation.
  11. 11 . The warpage amount estimation apparatus according to claim 1 , wherein the processor is further configured to perform the estimation using correlations which are different from each other according to a diameter of a substrate support on which the estimation target substrate is supported in a manner that a substrate peripheral edge portion overhangs when a camera images the estimation target substrate.
  12. 12 . The warpage amount estimation apparatus according to claim 1 , wherein the processor is further configured to perform the calculation and the estimation, based on a pixel value of a predetermined color.
  13. 13 . The warpage amount estimation apparatus according to claim 1 , wherein the processor is further configured to calibrate a captured image of a rear surface of the estimation target substrate based on a captured image of a calibration substrate without warpage, and perform the calculation based on the calibrated captured image of the rear surface of the estimation target substrate.
  14. 14 . A warpage amount estimation method of estimating a warpage amount of a substrate, comprising: acquiring, by a processor, a captured image of an estimation target substrate; calculating, by the processor, a rate of change in pixel value continuously changing in a substrate radial direction in the captured image of the estimation target substrate; and estimating, by the processor, a warpage amount of the estimation target substrate based on a correlation obtained in advance between a rate of change in pixel value continuously changing in the substrate radial direction in a captured image of a substrate, and a warpage amount of the substrate, and on a calculation result of the calculated rate of change.
  15. 15 . The warpage amount estimation apparatus according to claim 1 , wherein the rate of change in pixel value in the substrate radial direction in the captured image of the estimation target substrate is caused by stress induced by a substrate treatment.
  16. 16 . The warpage amount estimation apparatus according to claim 1 , wherein the captured image of the estimation target substrate used for the estimation of the warpage amount of the estimation target substrate is acquired by a camera located on the side of the estimation target substrate.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation application of U.S. Utility application Ser. No. 18/249,630 filed on Apr. 19, 2023, which is a U.S. national stage application of PCT/JP2021/037850 filed on Oct. 13, 2021, which is based on and claims the benefit of priority of the prior Japanese Patent Application No. 2020-179639 filed on Oct. 27, 2020, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD This disclosure relates to a warpage amount estimation apparatus and a warpage amount estimation method. BACKGROUND ART The wafer treatment method disclosed in Patent Document 1 includes the steps of: imaging, with a camera, an end surface of a reference wafer over the entire peripheral edge of the reference wafer whose warpage amount is known, to acquire shape data on the end surface of the reference wafer over the entire peripheral edge of the reference wafer; imaging, with a camera, an end surface of a wafer over the entire peripheral edge of the wafer, to acquire shape data on the end surface of the wafer over the entire peripheral edge of the wafer; and calculating a warpage amount of the wafer on the basis of the shape data. The above treatment method further includes the steps of: forming a resist film on a front surface of the wafer; and deciding a supply position of an organic solvent to a peripheral edge portion of the resist film on the basis of the warpage amount, and dissolving the peripheral edge portion with the organic solvent supplied from the supply position to remove it from the top of the wafer. PRIOR ART DOCUMENT Patent Document Patent Document 1: Japanese Laid-open Patent Publication No. 2017-150849 DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The technique according to this disclosure makes it possible to estimate a warpage amount of a substrate without increasing the size of an apparatus even when the warpage of the substrate is large. Means for Solving the Problems An aspect of this disclosure is a warpage amount estimation apparatus for estimating a warpage amount of a substrate, including: an acquirer configured to acquire a captured image of one surface of an estimation target substrate; a calculator configured to calculate a rate of change in pixel value relating to a substrate radial direction in the captured image of the one surface of the estimation target substrate; and an estimator configured to estimate a warpage amount of the estimation target substrate based on a correlation obtained in advance between a rate of change in pixel value relating to the substrate radial direction in a captured image of the one surface of a substrate and a warpage amount of the substrate, and on a calculation result by the calculator. Effect of the Invention According to this disclosure, it is possible to estimate a warpage amount of a substrate without increasing the size of an apparatus even when the warpage of the substrate is large. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view illustrating the outline of a configuration of a wafer treatment system including a warpage amount estimation apparatus according to this embodiment. FIG. 2 is a view schematically illustrating the outline of an internal configuration on a front side of the wafer treatment system according to this embodiment. FIG. 3 is a view schematically illustrating the outline of the internal configuration on a rear side of the wafer treatment system according to this embodiment. FIG. 4 is a transverse sectional view illustrating the outline of a configuration of an inspection apparatus. FIG. 5 a longitudinal sectional view illustrating the outline of the configuration of the inspection apparatus. FIG. 6 is a block diagram schematically illustrating the outline of a configuration of a controller. FIG. 7 is a view illustrating a wafer in a state where no warpage occurs and a wafer in a state where warpage occurs. FIG. 8 is a view illustrating an example of a captured image of a peripheral edge portion of a rear surface of the wafer. FIG. 9 is a flowchart for explaining an example of a flow of processing by the controller. FIG. 10 is a view illustrating an example of an abnormal portion. FIG. 11 is a view illustrating another example of the abnormal portion. FIG. 12 is a view illustrating another example of the abnormal portion. FIG. 13 is a view illustrating an example of a region relating to a wafer circumferential direction used for estimation of the warpage amount in a captured image of the peripheral edge portion of the rear surface of the wafer. FIG. 14 is a view illustrating another example of the region relating to the wafer circumferential direction used for estimation of the warpage amount in the captured image of the peripheral edge portion of the rear surface of the wafer. FIG. 15 is a view for explaining an example of a pixel value used for estimation or the like of the warpage amount. FIG. 16 is a chart illustrating an estimated