Claims
- 1. A method of repairing a defect in a photolithography mask, comprising:
obtaining topographical data on a defect using a scanning probe microscope; transferring the topographical data to a charged particle beam system; generating a topographical data image; obtaining a charged particle beam image of the defect area; superimposing the topographical data image over the charged particle beam image; aligning visible features in the two images; using the topographical data to determine appropriate charged particle beam dose to repair the defect; and directing a charged particle beam at the defect.
- 2. The method of claim 1 in which the topographical data on the defect is used to generate a three-dimensional bitmap of the defect area.
- 3. The method of claim 1 in which the density of the topographical data image can be adjusted to make the image more transparent or less transparent.
- 4. The method of claim 1 in which using the topographical data to determine appropriate charged particle beam dose to repair the defect comprises:
determining the etch rate for the defect material; generating a sequence of dwell points adequate to repair the defect; determining the elevation of each dwell point from the topographical data; assigning the dwell points with the maximum elevation a full charged particle beam dose sufficient to repair the dwell points; assigning lower dwell points a proportionate percentage of the full charged particle beam dose; determining the surface angle for each dwell point; and applying a slope correction to the assigned beam dose for each dwell point.
- 5. The method of claim 4 further comprising dividing the maximum defect height into a number of height steps and assigning each dwell points to a height step based upon the elevation of each dwell point.
- 6. A method of repairing a bump defect in a phase shift photolithography mask, comprising:
obtaining topographical data on a bump defect using a scanning probe microscope; transferring the topographical data to a charged particle beam system; generating a topographical data image; obtaining a charged particle beam image of the defect area; superimposing the topographical data image over the charged particle beam image; aligning visible features in the two images; using the topographical data to determine appropriate charged particle beam dose to repair the defect; and directing a charged particle beam at the defect.
- 7. The method of claim 6 in which the topographical data on the defect is used to generate a three-dimensional bitmap of the defect area.
- 8. The method of claim 6 in which the density of the topographical data image can be adjusted to make the image more transparent or less transparent.
- 9. The method of claim 6 in which using the topographical data to determine appropriate charged particle beam dose to repair the defect comprises:
determining the etch rate for the defect material; generating a sequence of dwell points adequate to repair the defect; determining the elevation of each dwell point from the topographical data; assigning the dwell points with the maximum elevation a full charged particle beam dose sufficient to repair the dwell points; assigning lower dwell points a proportionate percentage of the full charged particle beam dose; determining the surface angle for each dwell point; and applying a slope correction to the assigned beam dose for each dwell point.
- 10. The method of claim 9 further comprising dividing the maximum defect height into a number of height steps and assigning each dwell points to a height step based upon the elevation of each dwell point.
- 11. A method of repairing a divot defect in a phase shift photolithography mask, comprising:
obtaining topographical data on a divot defect using a scanning probe microscope; transferring the topographical data to a charged particle beam system; generating a topographical data image; obtaining a charged particle beam image of the defect area; superimposing the topographical data image over the charged particle beam image; aligning visible features in the two images; using the topographical data to determine appropriate charged particle beam dose to repair the defect; and directing a charged particle beam at the defect.
- 12. The method of claim 11 in which the topographical data on the defect is used to generate a three-dimensional bitmap of the defect area.
- 13. The method of claim 11 in which the density of the topographical data image can be adjusted to make the image more transparent or less transparent
- 14. A method of directing a charged particle beam system using topographical data from an SPM scan of a defect area comprising:
generating a topographical data image of the defect area from the topographical data from an SPM scan; superimposing the topographical data image over a charged particle beam image of the defect area; and adjusting the position of the images to accurately align the topographical data image with the charged particle beam image.
- 15. The method of claim 14 in which area scanned by the SPM and by the charged particle beam system includes distinct non-defect features.
- 16. The method of claim 14 in which in which the density of the topographical data image can be adjusted to make the image more transparent or less transparent.
- 17. The method of claim 15 in which in which the density of the topographical data image can be adjusted to make the image more transparent or less transparent.
- 18. A method of using topographical data to calculate the charged particle beam dose for each dwell point within a bump defect comprising:
determining the etch rate for the defect material; generating a sequence of dwell points adequate to repair the defect; determining the elevation of each dwell point from the topographical data; assigning the dwell points with the maximum elevation a full charged particle beam dose sufficient to repair the dwell points; assigning lower dwell points a proportionate percentage of the full charged particle beam dose; determining the surface angle for each dwell point; and applying a slope correction to the assigned beam dose for each dwell point.
- 19. The method of claim 18 further comprising dividing the maximum defect height into a number of height steps and assigning each dwell points to a height step based upon the elevation of each dwell point.
- 20. A system for repairing a defect in a photolithography mask, comprising:
a means for obtaining topographical data on a defect; a means for transferring the topographical data to a charged particle beam system; a means for generating a topographical data image; a means for obtaining a charged particle beam image of the defect area; a means for superimposing the topographical data image over the charged particle beam image; a means for aligning visible features in the two images; a means for using the topographical data to determine appropriate charged particle beam dose to repair the defect; and a means for directing a charged particle beam at the defect.
- 21. An apparatus for repairing a defect in a photolithography mask, comprising:
a device for determining topological features of a defect area; a device for processing topological data, generating a topographical image of a defect area, and storing the data and the topographical image in memory; a display unit for displaying the topographical image; a charged particle beam system having a charged particle source for emitting a charged particle beam, an optical system for focusing the charged particle beam, a computer controlled beam deflector to position the charged particle beam, a secondary charged particle detector for detecting secondary charged particles and outputting a corresponding signal, and a display unit for displaying a charged particle beam image; a processor for aligning the topographical image and the charged particle beam image, and for using the topographical data to control the charged particle beam.
- 22. The apparatus of claim 21 in which the device for determining topological features of a defect area is a scanning probe microscope.
- 23. The apparatus of claim 21 in which the charged particle beam system is a focused ion beam system.
- 24. The apparatus of claim 21 in which using the topographical data to control the beam comprises:
generating a sequence of dwell points adequate to repair the defect; determining the elevation of each dwell point from the topographical data; assigning the dwell points with the maximum elevation a full charged particle beam dose sufficient to repair the dwell points; assigning lower dwell points a proportionate percentage of the full charged particle beam dose; determining the surface angle for each dwell point; and applying a slope correction to the assigned beam dose for each dwell point.
Parent Case Info
[0001] The application claims priority from U.S. Provisional Patent Application No. 60/402,010, which was filed Aug. 8, 2002 and which is hereby incorporated by reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60402010 |
Aug 2002 |
US |