Methods and systems for classifying defects detected on a reticle

• US 8,204,297 B1
• Filed: 02/27/2009
• Issued: 06/19/2012
• Est. Priority Date: 02/27/2009
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: KLA-Tencor Corporation
• Inventors: Xiong, Yalin, Hess, Carl
• Primary Examiner(s): PHAM, HOA Q
• Application Number:
  US12/394,752
• Time in Patent Office: 1,208 Days
• Field of Search: 382144-154, 3562371-2375, 702/108
• US Class Current: 382/149
• CPC Class Codes: G01N 2021/95676 Masks, reticles, shadow masks
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G03F 1/84 Inspecting

Abstract

Methods and systems for classifying defects detected on a reticle are provided. One method includes determining an impact that a defect detected on a reticle will have on the performance of a device being fabricated on a wafer based on how at least a portion of the reticle prints or will print on the wafer. The defect is located in the portion of the reticle. The method also includes assigning a classification to the defect based on the impact.

Claims

1. A method for classifying defects detected on a reticle, comprising:

determining an impact that a defect detected on a reticle will have on the performance of a device being fabricated on a wafer based on how at least a portion of the reticle prints or will print on the wafer and based on how at least another portion of the reticle prints or will print on the wafer, wherein the defect is located in the portion of the reticle, and wherein another defect is located in the other portion of the reticle; and

assigning a classification to the defect based on the impact.

2. The method of claim 1, further comprising generating a simulated image that illustrates how at least the portion of the reticle will print on the wafer using an image of at least the portion of the reticle, wherein the image is generated by inspection of the reticle, and wherein said determining comprises determining the impact based on the simulated image.

3. The method of claim 1, further comprising generating an aerial image that illustrates how at least the portion of the reticle will print on the wafer, wherein the aerial image is generated by inspection of the reticle, and wherein said determining comprises determining the impact based on the aerial image.

4. The method of claim 1, further comprising generating an image of at least a portion of the wafer in which at least the portion of the reticle is printed, wherein the image is generated by inspection of the wafer, and wherein said determining comprises determining the impact based on the image.

5. The method of claim 1, wherein said determining comprises simulating the impact that the defect will have on the performance of the device.

6. The method of claim 1, wherein the performance of the device comprises one or more electrical characteristics of the device, one or more thermal characteristics of the device, or some combination thereof.

7. The method of claim 1, wherein said determining is performed online during inspection of the reticle.

8. The method of claim 1, further comprising determining if the defect is to be reported in inspection results for the reticle based on the classification assigned to the defect.

9. The method of claim 1, wherein said determining is performed offline after inspection of the reticle.

10. The method of claim 1, wherein said determining comprises determining the impact based on how at least the portion of the reticle prints or will print on the wafer and based on how at least a portion of an additional reticle prints or will print on the wafer, and wherein the reticle and the additional reticle are printed or will be printed on different layers of the wafer.

11. The method of claim 1, wherein the performance of the device comprises the performance of only a portion of the device.

12. The method of claim 1, wherein the performance of the device comprises the performance of the entire device.

13. The method of claim 1, further comprising determining if the defect should be reviewed based on the classification and not based on information about the portion of the reticle in which the defect is located.

14. The method of claim 1, further comprising determining if the defect should be repaired based on the classification and not based on information about the portion of the reticle in which the defect is located.

15. The method of claim 1, further comprising determining if the reticle should be discarded based on the classification and not based on information about the portion of the reticle in which the defect is located.

16. The method of claim 1, wherein said determining and said assigning are performed for all defects detected on the reticle.

17. The method of claim 1, further comprising determining if defects detected on the reticle print or will print on the wafer based on how at least portions of the reticle corresponding to locations of the defects print or will print on the wafer, wherein said determining and said assigning are performed for only defects that print or will print on the wafer.

18. A system configured to classify defects detected on a reticle, comprising:

an inspection subsystem configured to detect a defect on a reticle and to acquire an image of at least a portion of the reticle in which the defect is located, wherein another defect is located in another portion of the reticle; and

a computer subsystem configured to generate a simulated image that illustrates how at least the portion of the reticle will print on a wafer using the image, determine an impact that the defect will have on the performance of a device being fabricated on the wafer based on the simulated image and based on how at least the other portion of the reticle prints or will print on the wafer, and assign a classification to the defect based on the impact.

19. A system configured to classify defects detected on a reticle, comprising:

an inspection subsystem configured to acquire an image that illustrates how at least a portion of a reticle prints or will print on a wafer, wherein a defect detected on the reticle is located in the portion of the reticle, and wherein another defect is located in another portion of the reticle; and

a computer subsystem configured to determine an impact that the defect will have on the performance of a device being fabricated on the wafer based on the image and based on how at least the other portion of the reticle prints or will print on the wafer and to assign a classification to the defect based on the impact.