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

• US 20130202187A1
• 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 8,855,399 B2
• Time in Patent Office: Days
• US Class Current: 382/149
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 2201/10 Scanning
• CPC Class Codes: G01N 2201/125 Digital circuitry
• CPC Class Codes: G01N 2201/127 Calibration; base line adjustment; drift compensation
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/0008 checking presence/absence
• CPC Class Codes: G06T 7/32 using correlation-based methods

Abstract

A system for location based wafer analysis, the system comprising: (i) a first input interface; (ii) a second input interface; (iii) a correlator; and (iv) a processor, configured to generate inspection results for the inspected wafer, with the help of at least one frame run-time displacement.

Claims

1. A system for location based wafer analysis, the system comprising:

a first input interface configured to obtain;

(a) calibration information that includes displacements of multiple frames included in a wafer area of a reference wafer, and (b) a target database that includes a target image and location information for each out of multiple targets in each of the multiple frames;

a second input interface, configured to obtain scanning image data of a scan of an inspected area of an inspected wafer;

a correlator, configured to;

(a) define for each out of multiple targets of the database a search window, based on the displacement of the frame in which the target is included;

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

(c) determine a frame run-time displacement for each of multiple run-time frames scanned, based on the target run-time displacements determined for multiple targets in the respective run-time frame; and

a processor, configured to generate inspection results for the inspected wafer, with the help of at least one of the frame run-time displacements.

2. The system according to claim 1, wherein the processor is configured to detect defects in the inspected area with the help of at least one of the target run-time displacements, wherein the processor is configured to generate the inspection results in response to the detected defects.

3. The system according to claim 1, further comprising a processor which is configured to improve location accuracy of a scanning of at least one of the run-time frames by a sensor that scans the inspected area, based on the frame run-time displacement determined for another run-time frame.

4. The system according to claim 1, wherein the first input interface is configured to obtain the location information in computer aided design (CAD) coordinates.

5. The system according to claim 1, wherein the defect detection module is configured to report detected defects and to report location information of at least one of the defects in CAD coordinates.

6. The system according to claim 1, wherein the correlator is configured to:

(a) modify a comparison scheme based on the frame run-time displacement of the multiple run-time frames; and

(b) compare an image obtained at the scanning to reference data, based on the modified comparison scheme;

wherein the defect detection module is configured to detect the defects based on results of the comparing.

7. The system according to claim 1, wherein the second input interface is configured to receive scanning image data of a series of inspected wafer areas, each of which covers a different die;

wherein the correlator is configured to perform the following actions for each of the other wafer areas, other than the first;

(a) defining search windows which correspond to a subgroup which includes at least some of the database targets, wherein the defining of each of the search windows is based on a frame run-time displacement determined for a previous inspected wafer area of the series, wherein the size of at least one of the search windows is smaller than the size of a search window defined for the corresponding target in the inspected area;

(b) calculating a target run-time displacement for each of the targets of the subgroup, based on a correlation of the respective target image to a scanned image of the corresponding search window; and

(c) detecting defects in the inspected wafer area, wherein the detecting is responsive to at least one of the target run-time displacements.

8. A computerized method for location based wafer analysis, the method comprising:

obtaining;

(a) calibration information that includes displacements of multiple frames included in a wafer area of a reference wafer, and (b) a target database that includes a target image and location information for each out of multiple targets in each of the multiple frames;

scanning an inspected area of an inspected wafer to provide a scanned image of the inspected area;

for each out of multiple targets of the database;

(a) defining a corresponding search window based on the displacement of the frame in which the target is included; and

(b) calculating a run-time displacement for the target, based on a correlation of the target image of the target 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, based on the target run-time displacements calculated for targets of the respective run-time frame; and

providing inspection results for the inspected wafer, with the help of at least one of the frame run-time displacements.

9. The method according to claim 8, further comprising detecting defects in the inspected area with the help of at least one of the target run-time displacements, wherein the providing comprises providing results of the defect detection.

10. The method according to claim 8, wherein the scanning of the inspected area comprises improving location accuracy of the scanning of at least one of the run-time frames based on the frame run-time displacement determined for another run-time frame.

11. The method according to claim 8, wherein the obtaining of the location information of the targets includes obtaining the location information in computer aided design (CAD) coordinates.

12. The method according to claim 8, further comprising reporting defects, after the detecting, wherein the reporting comprises reporting location information of at least one of the defects in CAD coordinates.

13. The method according to claim 8, further comprising modifying a comparison scheme based on the frame run-time displacement of the multiple run-time frames;

and comparing an image obtained at the scanning to reference data, based on the modified comparison scheme;

wherein the detecting of the defects is based on results of the comparing.

14. The method according to claim 8, wherein the scanning of the inspected area is the first in a series of scanning of multiple inspected wafer areas, each of which covers a different die;

and for each of the inspected wafer areas other than the first;

defining search windows which correspond to a subgroup which includes at least some of the database targets, wherein the defining of each of the search windows is based on a frame run-time displacement determined for a previous inspected wafer area of the series, wherein the size of at least one of the search windows is smaller than the size of a search window defined for the corresponding target in the inspected area;

calculating a target run-time displacement for each of the targets of the subgroup, based on a correlation of the respective target image to a scanned image of the corresponding search window; and

detecting defects in the inspected wafer area, wherein the detecting is responsive to at least one of the target run-time displacements.

15. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method for wafer analysis, comprising the steps of:

(a) obtaining;

(i) calibration information that includes displacements of multiple frames included in a wafer area of a reference wafer, and (ii) a target database that includes a target image and location information for each out of multiple targets in each of the multiple frames;

(b) scanning an inspected area of an inspected wafer to provide a scanned image of the inspected area;

(c) for each out of multiple targets of the database;

(i) defining a corresponding search window based on the displacement of the frame in which the target is included; and

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

(d) determining a frame run-time displacement for each of multiple run-time frames scanned, based on the target run-time displacements calculated for targets of the respective run-time frame; and

(e) providing inspection results for the inspected wafer, with the help of at least one of the frame run-time displacements.

16. The program storage device according to claim 15, wherein the program of instructions further includes computer readable program code for causing the machine to detect defects in the inspected area with the help of at least one of the target run-time displacements, wherein the providing comprises providing results of the defect detection.

17. The program storage device according to claim 15, wherein the computer readable program code that is included in the program of instructions for causing the machine to perform the step of scanning the inspected area comprises instructions for improving location accuracy of the scanning of at least one of the run-time frames based on the frame run-time displacement determined for another run-time frame.

18. The program storage device according to claim 15, wherein the computer readable program code that is included in the program of instructions for causing the machine to perform the step of obtaining of the location information of the targets includes instructions for obtaining the location information in computer aided design (CAD) coordinates.

19. The program storage device according to claim 15, wherein the program of instructions further includes computer readable program code for causing the machine to report defects, after the detecting, wherein the reporting of the defects comprises reporting location information of at least one of the defects in CAD coordinates.

20. The program storage device according to claim 15, wherein the program of instructions further includes computer readable program code for causing the machine to modify a comparison scheme based on the frame run-time displacement of the multiple run-time frames;

and to compare an image obtained at the scanning to reference data, based on the modified comparison scheme;

wherein the detecting of the defects is based on results of the comparing.