Methods of detecting defects in registration controlled photomasks

Patent metadata

Field	Value
Publication number	US-10026166-B2
Application number	US-201614988471-A
Country	US
Kind code	B2
Filing date	Jan 5, 2016
Priority date	Aug 4, 2015
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A method of detecting defects of a photomask includes measuring registration errors of the photomask, correcting the measured registration errors using a registration control process with a laser beam, extracting deformation data of the photomask deformed by the registration control process, reflecting the extracted deformation data in defect detection parameters to obtain compensated defect detection parameters, and detecting defects of the photomask using the compensated defect detection parameters.

First claim

What is claimed is:

1. A method of detecting defects of a photomask, the method comprising:
measuring registration errors of the photomask;
correcting the measured registration errors using a registration control process with a laser beam;
extracting deformation data of the photomask deformed by the registration control process;
reflecting the extracted deformation data in defect detection parameters to obtain compensated defect detection parameters; and
detecting defects of the photomask using the compensated defect detection parameters,
wherein the photomask is expanded during the registration control process, and
wherein the registration control process includes expanding the photomask two opposite directions from an intersecting line.

2. The method of claim 1 , wherein measuring the registration errors of the photomask is performed after photomask patterns are formed.

3. The method of claim 1 , wherein the registration control process is performed by irradiating the laser beam onto the photomask to correct local position errors of the photomask patterns.

4. The method of claim 1 , wherein the deformation data of the photomask includes vector information on degrees of expansion of the photomask to which the registration control process is applied.

5. The method of claim 4 , wherein reflecting the extracted deformation data in the defect detection parameters is performed by reflecting compensation vector information for compensating the vector information in the defect detection parameters in each of regions of the photomask.

6. The method of claim 5 , wherein the compensation vector information includes information on compensation vectors having the same magnitudes and opposite orientations as vectors constituting the vector information.

7. The method of claim 1 , wherein the defects of the photomask include haze.

8. The method of claim 1 , wherein detecting defects of the photomask using the compensated defect detection parameters further comprises reflecting compensation vectors applied to all regions of the photomask.

9. The method of claim 1 , wherein registration errors are measured by a metrological apparatus.

10. The method of claim 1 further comprising correcting overlay error while correcting measured registration errors.

11. The method of claim 1 further comprising performing a registration compensation process with a registration control system, wherein the measured registration error are corrected using the registration compensation process.

12. The method of claim 1 further comprising, during the registration control process, using a laser beam to irradiate the photomask to generate a deformation in a quartz substrate of the photomask.

13. The method of claim 1 further comprising extracting measurements of the deformation data of the photomask using a metrological apparatus.

14. The method of claim 1 further comprising measuring the registration of the photomask after performing a registration control process.

15. The method of claim 1 wherein an initial registration is measured before the registration control process is performed.

16. The method of claim 1 , wherein extracted deformed data is applied to the defect detection parameters to obtain compensated defect detection parameters.

17. The method of claim 1 , wherein the defect detection parameters include reference pattern image information.

18. The method of claim 17 , wherein the reference pattern image information is obtained from the photomask before the registration control process.

Assignees

• Sk Hynix Inc

Inventors

• Jeong Goo Min

Classifications

• H05K2203/16

  Inspection; Monitoring; Aligning · CPC title

• G06T7/001 Primary

  using an image reference approach · CPC title

• G06T7/30

  Determination of transform parameters for the alignment of images, i.e. image registration · CPC title

• H05K2203/166

  Alignment or registration; Control of registration · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title