Defect detection using structural information

Patent metadata

Field	Value
Publication number	US-9727047-B2
Application number	US-201514880187-A
Country	US
Kind code	B2
Filing date	Oct 9, 2015
Priority date	Oct 14, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Systems and methods for detecting defects on a specimen based on structural information are provided. One system includes one or more computer subsystems configured for separating the output generated by a detector of an inspection subsystem in an array area on a specimen into at least first and second segments of the output based on characteristic(s) of structure(s) in the array area such that the output in different segments has been generated in different locations in the array area in which the structure(s) having different values of the characteristic(s) are formed. The computer subsystem(s) are also configured for detecting defects on the specimen by applying one or more defect detection methods to the output based on whether the output is in the first segment or the second segment.

First claim

What is claimed is:

1. A system configured to detect defects on a specimen based on structural information, comprising:
an inspection subsystem comprising at least an energy source and a detector, wherein the energy source is configured to generate energy that is directed to a specimen, and wherein the detector is configured to detect energy from the specimen and to generate output responsive to the detected energy; and
one or more computer subsystems configured for:
separating the output generated by the detector in an array area on the specimen into at least first and second segments of the output based on one or more characteristics of one or more structures in the array area such that the output in different segments has been generated in different locations in the array area in which the one or more structures having different values of the one or more characteristics are formed, wherein said separating comprises determining symmetry scores for different regions in the output. and a design for the wafer, aligning symmetry scores for the output to the symmetry scores for the design, and separating the output based on results of said aligning and information about which of the one or more structures correspond to the symmetry scores for the design; and
detecting defects on the specimen by applying one or more defect detection methods to the output based on whether the output is in the first segment or the second segment.

2. The system of claim 1 , wherein said separating is not based on one or more characteristics of the output.

3. The system of claim 1 , wherein the one or more characteristics of the structures are determined based on one or more scanning electron microscope images of the specimen or another specimen of the same type as the specimen.

4. The system of claim 1 , wherein said separating further comprises correlating one or more scanning electron microscope images of the specimen or another specimen of the same type as the specimen with the output and transferring the one or more characteristics of the one or more structures from the one or more scanning electron microscope images to the output correlated thereto.

5. The system of claim 1 , wherein the one or more characteristics of the structures are determined based on a design for the specimen.

6. The system of claim 1 , wherein said separating further comprises correlating a design for the specimen with the output and transferring the one or more characteristics of the one or more structures from the design to the output correlated thereto.

7. The system of claim 1 , wherein the one or more computer subsystems are further configured for locating the one or more structures in the output based on the output generated for one or more unique structures formed on the specimen and a spatial relationship between the one or more unique structures and the one or more structures.

8. The system of claim 1 , wherein the one or more characteristics comprise a repeating pitch of the one or more structures.

9. The system of claim 1 , wherein the one or more computer subsystems are further configured for determining the values of the one or more characteristics of the one or more structures in which the defects are detected and storing the determined values as defect attributes for the defects.

10. The system of claim 1 , wherein the one or more characteristics comprise one or more topologic characteristics of the one or more structures.

11. The system of claim 1 , wherein the one or more characteristics comprise symmetrical and asymmetrical characteristics of the one or more structures.

12. The system of claim 1 , wherein the first and second segments are located in one or more care areas.

13. The system of claim 1 , wherein said separating further comprises applying one or more rules to the output, and wherein the one or more rules are based on differences in the one or more characteristics between different types of the one or more structures.

14. The system of claim 1 , wherein said applying comprises determining one or more characteristics of noise for the first segment based on only the output in the first segment and determining one or more parameters of the one or more defect detection methods based on the determined one or more characteristics of the noise.

15. The system of claim 1 , wherein the one or more defect detection methods applied to the output in the first segment have a different detection sensitivity than the one or more defect detection methods applied to the output in the second segment.

16. The system of claim 1 , wherein said applying comprises applying the one or more defect detection methods having a first set of parameters to only the output included in the first segment and applying the one or more defect detection methods having a second set of parameters different from the first set of parameters to only the output included in the second segment.

17. A non-transitory computer-readable medium, storing program instructions executable on a computer system for performing a computer-implemented method for detecting defects on a specimen based on structural information, wherein the computer-implemented method comprises:
separating output generated by a detector of an inspection subsystem in an array area on a specimen into at least first and second segments of the output based on one or more characteristics of one or more structures in the array area such that the output in different segments has been generated in different locations in the array area in which the one or more structures having different values of the one or more characteristics are formed, wherein the inspection subsystem comprises at least an energy source and the detector, wherein the energy source is configured to generate energy that is directed to the specimen, wherein the detector is configured to detect energy from the specimen and to generate output responsive to the detected energy, and wherein said separating comprises determining symmetry scores for different regions in the output and a design for the wafer, aligning the symmetry scores for the output to the symmetry scores for the design, and separating the output based on results of said aligning and information about which of the one or more structures correspond to the symmetry scores for the design; and
detecting defects on the specimen by applying one or more defect detection methods to the output based on whether the output is in the first segment or the second segment.

18. A computer-implemented method for detecting defects on a specimen based on structural information, comprising:
separating output generated by a detector of an inspection subsystem in an array area on a specimen into at least first and second segments of the output based on one or more characteristics of one or more structures in the array area such that the output in the different segments has been generated in different locations in the array area in which the one or more structures having different values of the one or more characteristics are formed, wherein the inspection subsystem comprises at least an energy source and the detector, wherein the energy source is configured to generate energy that is directed to the specimen, wherein the detector is configured to detect energy from the specimen and to generate output responsive to the detected energy, and wherein said separating comprises determining symmetry scores for different regions in the output and a design for the wafer, aligning the symmetry scores for the output to the symmetry scores for the design, and separating the out

Assignees

• Kla Tencor Corp
• Kla Tencor Corp

Inventors

• Luo Qing
• Wu Kenong
• Lee Hucheng
• Gao Lisheng
• Shifrin Eugene
• Xiong Yan
• Sun Shuo

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• G05B2219/37571

  Camera detecting reflected light from laser · CPC title

• H01J2237/2817

  Pattern inspection · CPC title

• G05B2219/37365

  Surface shape, gradient · CPC title