SYSTEM, A METHOD AND A COMPUTER PROGRAM PRODUCT FOR CAD-BASED REGISTRATION

• US 20130204569A1
• Filed: 02/07/2012
• Published: 08/08/2013
• Est. Priority Date: 02/07/2012
• Status: Active Grant

• Current Assignee: Applied Materials Israel Limited (Applied Materials Incorporated)
• Original Assignee: Applied Materials Israel Limited (Applied Materials Incorporated)
• Inventors: Goren, Zvi, Ben-David Dodzin, Nir
• Granted Patent: US 9,599,575 B2
• Time in Patent Office: Days
• US Class Current: 702/117
• CPC Class Codes: G01N 2021/95615 with stored comparision signal
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10

Abstract

A system for generating calibration information usable for wafer inspection, the system including: (I) a displacement analysis module, configured to: (a) calculate a displacement for each target out of multiple targets selected in multiple scanned frames which are included in a scanned area of the wafer, the calculating based on a correlation of: (i) an image associated with the respective target which was obtained during a scanning of the wafer, and (ii) design data corresponding to the image; and (b) determining a displacement for each of the multiple scanned frames, the determining based on the displacements calculated for multiple targets in the respective scanned frame; and (II) a subsequent processing module, configured to generate calibration information including the displacements determined for the multiple scanned frames, and a target database that includes target image and location information of each target of a group of database targets.

Claims

1. A system for generating calibration information usable for wafer inspection, the system comprising:

a displacement analysis module, configured to;

(a) calculate a displacement for each target out of multiple targets selected in multiple scanned frames which are included in a scanned area of the wafer, the calculating based on a correlation of;

(i) an image associated with the respective target which was obtained during a scanning of the wafer, and (ii) design data corresponding to the image; and

(b) determining a displacement for each of the multiple scanned frames, the determining based on the displacements calculated for multiple targets in the respective scanned frame; and

a subsequent processing module, configured to generate;

(a) calibration information including the displacements determined for the multiple scanned frames, and (b) a target database that includes target image and location information of each target of a group of database targets, the group including multiple targets in each of the multiple scanned frames.

2. The system according to claim 1, wherein the subsequent processing module is configured to save the location information of the database targets in computer aided design (CAD) coordinates.

3. The system according to claim 1, further comprising an image processing module that is configured to:

(a) select the image for each of the multiple targets based on image processing of the scanned image data; and

(b) define the scanned frames based on image processing of the scanned image data.

4. The system according to claim 1, further comprising:

an input interface for receiving scanned image data of a second wafer area other than the scanned area;

a correlator, configured to;

(a) define search windows, each of which corresponds to one of the database targets, wherein the defining of each of the search windows is based on the determined displacement of the respective scanned-frame in which the corresponding target is included; and

(b) calculate a run-time displacement for each out of multiple database targets, based on a correlation of the respective target image to at least a portion of a scanned image of the corresponding search window; and

a defect detection module, configured to detect defects in the second wafer area with the help of at least one of the target run-time displacements.

5. The system according to claim 4, further comprising an output interface configured to report at least some of the defects, wherein the reporting comprises reporting location information of at least one of the defects in coordinates of the design data.

6. The system according to claim 4, wherein the correlator is configured to determine a frame run-time displacement for each of multiple run-time frames scanned in the second wafer area, based on the target run-time displacements determined for multiple targets in the respective run-time frame;

wherein the defect detection module is further configured to modify a comparison scheme based on the frame run-time displacement of the multiple run-time frames;

wherein the defect detection module is configured to compare a scanned image of at least a portion of the second wafer area to reference data, based on the modified comparison scheme and to detect defects in the second wafer area based on results of the comparing.

7. The system according to claim 1, further comprising an input interface for receiving scanning results of a scan of the scanned area of the wafer that was scanned in slices scanned in alternating scanning directions;

wherein the subsequent processing module is configured to generate, as part of the calibration information, a first displacement map which includes frame-displacements of scanned frames scanned in a first scanning direction, and a second displacement map which includes frame-displacements of scanned frames scanned in a second scanning direction.

8. A computerized method for generating calibration information usable for wafer inspection, the method comprising:

determining a displacement for each of the multiple scanned frames, the determining based on the displacements calculated for multiple targets in the respective scanned frame; and

generating;

(a) calibration information including the displacements determined for the multiple scanned frames, and (b) a target database that includes target image and location information of each target of a group of database targets, the group including multiple targets in each of the multiple scanned frames.

9. The method according to claim 8, the method comprising enabling utilizing the calibration information and the target database for determining location information in an inspection of another wafer.

10. The method according to claim 8, wherein the generating comprises saving the location information of the database targets in computer aided design (CAD) coordinates.

11. The method according to claim 8, further comprising:

scanning the scanned area of the wafer to provide scanned image data;

selecting the image for each of the multiple targets based on image processing of the scanned image data;

saving the multiple images based on the selection; and

defining the scanned frames based on image processing of the scanned image data.

12. The method according to claim 8, wherein the generating is followed by:

scanning of a second wafer area other than the scanned area;

for each out of multiple targets of the database;

defining a corresponding search window based on the determined displacement of the scanned-frame in which the target is included; and

calculating a run-time displacement for the target, based on a correlation of the target image to at least a portion of an area of the scanned image which is defined by the corresponding search window;

determining a frame run-time displacement for each of multiple run-time frames scanned in the second wafer area, based on the target run-time displacements determined for multiple targets in the respective run-time frame; and

providing inspection results for a wafer which includes the second wafer area, with the help of at least one of the frame run-time displacements.

13. The method according to claim 12, further comprising detecting defects in the second wafer area with the help of at least one of the target run-time displacements, wherein the providing comprises providing results of the defect detection.

14. The method according to claim 12, further comprising reporting defects, after the detecting, wherein the reporting comprises reporting location information of at least one of the defects in coordinates of the design data.

15. The method according to claim 8, wherein the calculating is preceded by scanning the scanned area of the wafer in slices which are scanned in alternating scanning directions;

wherein the generating of the calibration information comprises generating a first displacement map which includes frame-displacements of scanned frames scanned in a first scanning direction, and a second displacement map which includes frame-displacements of scanned frames scanned in a second scanning direction.

16. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method for generating calibration information usable for wafer inspection, comprising the steps of:

(a) determining a displacement for each of the multiple scanned frames, the determining based on the displacements calculated for multiple targets in the respective scanned frame; and

(b) generating (i) calibration information including the displacements determined for the multiple scanned frames, and (ii) a target database that includes target image and location information of each target of a group of database targets, the group including multiple targets in each of the multiple scanned frames.

17. The program storage device according to claim 16, wherein the program of instructions further includes computer readable program code for causing the machine to enable utilizing the calibration information and the target database for determining location information in an inspection of another wafer.

18. The program storage device according to claim 16, wherein the computer readable program code that is included in the program of instructions for causing the machine to perform the step of generating comprise instructions for saving the location information of the database targets in computer aided design (CAD) coordinates.

19. The program storage device according to claim 16, wherein the program of instructions further includes computer readable program code for causing the machine to:

(a) scan the scanned area of the wafer to provide scanned image data;

(b) select the image for each of the multiple targets based on image processing of the scanned image data;

(c) save the multiple images based on the selection; and

(d) define the scanned frames based on image processing of the scanned image data.

20. The program storage device according to claim 16, wherein the program of instructions further includes computer readable program code for causing the machine to report defects, after the detecting, wherein the reporting comprises reporting location information of at least one of the defects in coordinates of the design data.