Defect sensitivity of semiconductor wafer inspectors using design data with wafer image data

Patent metadata

Field	Value
Publication number	US-10127651-B2
Application number	US-201615356729-A
Country	US
Kind code	B2
Filing date	Nov 21, 2016
Priority date	Jan 15, 2016
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

Criticality of a detected defect can be determined based on context codes. The context codes can be generated for a region, each of which may be part of a die. Noise levels can be used to group context codes. The context codes can be used to automatically classify a range of design contexts present on a die without needing certain information a priori.

First claim

What is claimed is:

1. A system comprising:
a review tool, wherein the review tool includes:
a stage configured to hold a wafer; and
an image generation system configured to generate an image of the wafer; and

a controller in electronic communication with the review tool, wherein the controller is configured to:
separate a design file into a plurality of regions, wherein the design file is of a die of the wafer;
generate a context code for each of the regions, wherein the context code is configured to encode geometry of one of the regions;
align an image of the die of the wafer to the design file at the die;
group the context codes into one or more inspection sensitivity regions based on a noise level of each of the regions;
scan the die using the inspection sensitivity regions;
calculate a threshold for each of the inspection sensitivity regions;
examine the context code for pixels at a detected defect; and
determine a criticality of the detected defect based on one or more of the context codes.

2. The system of claim 1 , wherein the controller includes a processor, an electronic data storage unit in electronic communication with the processor, and a communication port in electronic communication with the processor and the electronic data storage unit.

3. The system of claim 2 , wherein the electronic data storage unit includes the design file.

4. The system of claim 1 , wherein the review tool is a scanning electron microscope.

5. The system of claim 1 , wherein the image generation system is configured to use at least one of an electron beam, a broad band plasma, or a laser to generate the image of the wafer.

6. The system of claim 1 , wherein the context code represents one or more of edge density, a vector of feature values, or a set of shape primitives of one of the regions.

7. The system of claim 1 , wherein the controller is further configured to analyze noise of the regions prior to grouping the context codes.

8. The system of claim 1 , wherein the controller is further configured to bin local geometry to capture at least one of line and space density measurement, line and space orientations, high curvature points, and line ends and object junctions.

9. A method comprising:
separating, using a controller, a design file into a plurality of regions, wherein the design file is of a die of a wafer;
generating, using the controller, a context code for each of the regions, wherein the context code is configured to encode geometry of one of the regions;
aligning, using the controller, an image of the die to the design file at the die;
grouping, using the controller, the context code into one or more inspection sensitivity regions based on a noise level of each of the regions;
scanning the die using the inspection sensitivity regions;
calculating, using the controller, a threshold for each of the inspection sensitivity regions;
examining, using the controller, the context code for pixels at a detected defect; and
determining, using the controller, a criticality of the detected defect based on one or more of the context codes.

10. The method of claim 9 , wherein the context code represents one or more of edge density, a vector of feature values, or a set of shape primitives of one of the regions.

11. The method of claim 9 , further comprising analyzing, using the processor, noise of the regions prior to the grouping.

12. The method of claim 9 , wherein the image of the die is a scanning electron microscope image.

13. The method of claim 9 , wherein the design file includes a plurality of layers disposed on one another.

14. The method of claim 9 , wherein the context code is configured to be a measure of edge density or a vector of feature values computed from the design file.

15. The method of claim 9 , wherein the context code is configured to be an encoding of a set of shape primitives in the region.

16. The method of claim 15 , wherein the encoding is frequency based and is configured to count existence of shape primitives in the region.

17. The method of claim 15 , wherein the encoding is of a spatial relationship between the shape primitives.

18. The method of claim 9 , further comprising binning local geometry, wherein the binning captures at least one of line and space density measurement, line and space orientations, high curvature points, and line ends and object junctions.

19. The method of claim 9 , wherein the design file is generated from a wafer image.

20. A non-transitory computer-readable storage medium, comprising one or more programs for executing the following steps on one or more computing devices:
separating a design file of a die of a wafer into a plurality of regions;
generating a context code for each of the regions, wherein the context code is configured to encode geometry of one of the regions;
aligning an image of the die to the design file at the die;
grouping the context code into one or more inspection sensitivity regions based on a noise level of each of the regions;
scanning the die using the inspection sensitivity regions;
calculating a threshold for each of the inspection sensitivity regions;
examining the context code for pixels at a detected defect; and
determining a criticality of the detected defect based on one or more of the context codes.

Assignees

• Kla Tencor Corp

Inventors

• Kulkarni Ashok
• Banerjee Saibal
• Bhattacharyya Santosh
• Brauer Bjorn

Classifications

• G06T2207/10061

  from scanning electron microscope · CPC title

• G06T7/0006 Primary

  using a design-rule based approach · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title

• G06T7/001 Primary

  using an image reference approach · CPC title

• H10P74/27

  Structural arrangements therefor · CPC title