Dynamic design attributes for wafer inspection

• US 9,865,512 B2
• Filed: 04/03/2014
• Issued: 01/09/2018
• Est. Priority Date: 04/08/2013
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: KLA-Tencor Corporation
• Inventors: Jayaraman, Thirupurasundari, Babulnath, Raghav
• Primary Examiner(s): Breene, John
• Assistant Examiner(s): Islam, Mohammad
• Application Number:
  US14/244,859
• Publication Number:
  US 20140303921A1
• Time in Patent Office: 1,377 Days
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14

Abstract

Methods and systems for dynamic design attributes for wafer inspection are provided. One method includes, at run time of a wafer inspection recipe, prompting a user of a wafer inspection tool on which the wafer inspection recipe is performed for information for a design based binning (DBB) process. The information includes one or more formulae for calculating design attributes from a design for a wafer. The design attributes are used to bin the defects in the DBB process. The method also includes performing inspection of a wafer according to an updated wafer inspection recipe. Performing the inspection includes binning defects detected on the wafer according to the DBB process in the updated wafer inspection recipe.

Claims

1. A method for wafer inspection, comprising:

at run time of a wafer inspection recipe, prompting a user of a wafer inspection tool on which the wafer inspection recipe is performed for information for a design based binning process, wherein the information comprises one or more formulae for calculating design attributes from a design for a wafer, wherein the calculated design attributes comprise overlap ratio of polygons in two or more layers of the design, and wherein the design attributes are used to bin the defects in the design based binning process;

receiving the information from the user;

updating the wafer inspection recipe based on the received information; and

performing inspection of the wafer according to the updated wafer inspection recipe, wherein said performing comprises;

scanning the wafer with the wafer inspection tool thereby generating output responsive to light from the wafer;

detecting defects on the wafer based on the output; and

binning the defects detected on the wafer according to the design based binning process in the updated wafer inspection recipe, wherein the prompting, receiving, updating, performing, scanning, detecting, and binning steps are performed by the wafer inspection tool.

2. The method of claim 1, wherein the one or more formulae comprise one or more formulae for calculating the design attributes from design data for the design surrounding locations of the defects detected on the wafer.

3. The method of claim 1, wherein the information comprises one or more layers of the wafer for which the design is used to calculate the design attributes.

4. The method of claim 1, wherein one or more parameters of the design based binning process are based on multi-layer design rules.

5. The method of claim 1, wherein the binning step separates the defects into different groups having different criticalities for pattern failure by applying design rule checks on design data for the wafer surrounding locations of the defects detected on the wafer.

6. The method of claim 1, wherein the binning step separates the defects that are nuisance defects into one or more first groups and the defects that are defects of interest into one or more second groups.

7. The method of claim 1, wherein the binning step shapes a sample of the defects that are defects of interest by separating different types of the defects of interest into different groups.

8. The method of claim 1, wherein the information further comprises flags for each of the design attributes indicating whether the design attributes are categorical attributes or measurement attributes.

9. The method of claim 1, wherein the binning step separates the defects based on design data for the wafer surrounding locations of the defects detected on the wafer, and wherein the information further comprises flags for each of the design attributes indicating an extent of the design data used to calculate the design attributes.

10. The method of claim 9, wherein the extent of the design data are an entirety of the design data or an area of interest within the design data.

11. The method of claim 1, wherein the information further comprises one or more layer operators for the one or more formulae, and wherein the one or more layer operators are one or more logical operators applied to polygons of two or more layers in the design.

12. The method of claim 11, wherein the one or more logical operators comprise one or more of logical AND, OR, XOR, and NOT operators.

13. The method of claim 11, wherein the information further comprises one or more calculations for the one or more formulae performed on polygons resulting from the one or more logical operators, and wherein the results of the one or more calculations are the calculated design attributes.

14. The method of claim 13, wherein the one or more calculations comprise one or more of:

counting a number of the polygons resulting from the one or more logical operators, counting a number of vertices in each of the polygons resulting from the one or more logical operators, summing an area of all of the polygons resulting from the one or more logical operators, determining a minimum area of all areas of the polygons resulting from the one or more logical operators, and determining a maximum area of all areas of the polygons resulting from the one or more logical operators.

15. The method of claim 1, wherein the calculated design attributes further comprise pattern density of polygons in the design.

16. The method of claim 1, wherein the wafer inspection tool is configured as a broadband plasma tool.

17. A non-transitory computer-readable medium, storing program instructions executable on a computer system of a wafer inspection tool for performing a computer-implemented method for wafer inspection, wherein the computer-implemented method comprises:

at run time of a wafer inspection recipe, prompting a user of the wafer inspection tool on which the wafer inspection recipe is performed for information for a design based binning process, wherein the information comprises one or more formulae for calculating design attributes from a design for the wafer, wherein the calculated design attributes comprise overlap ratio of polygons in two or more layers of the design, and wherein the design attributes are used to bin the defects in the design based binning process;

receiving the information from the user;

updating the wafer inspection recipe based on the received information; and

performing inspection of the wafer according to the updated wafer inspection recipe, wherein said performing comprises;

scanning the wafer with the wafer inspection tool thereby generating output responsive to light from the wafer;

detecting defects on the wafer based on the output; and

binning the defects detected on the wafer according to the design based binning process in the updated wafer inspection recipe.

18. A wafer inspection tool, comprising:

an optical subsystem configured to scan a wafer thereby generating output responsive to light from the wafer; and

a computer subsystem configured for;

at run time of a wafer inspection recipe, prompting a user of the wafer inspection tool on which the wafer inspection recipe is performed for information for a design based binning process, wherein the information comprises one or more formulae for calculating design attributes from a design for the wafer, wherein the calculated design attributes comprise overlap ratio of polygons in two or more layers of the design, and wherein the design attributes are used to bin the defects in the design based binning process;

receiving the information from the user;

updating the wafer inspection recipe based on the received information;

detecting defects on the wafer based on the output; and

binning the defects detected on the wafer according to the design based binning process in the updated wafer inspection recipe.

19. The wafer inspection tool of claim 18, wherein the one or more formulae comprise one or more formulae for calculating the design attributes from design data for the design surrounding locations of the defects detected on the wafer.

20. The wafer inspection tool of claim 18, wherein the information comprises one or more layers of the wafer for which the design is used to calculate the design attributes.

21. The wafer inspection tool of claim 18, wherein one or more parameters of the design based binning process a based on multi-layer design rules.

22. The wafer inspection tool of claim 18, wherein the binning step separates the defects into different groups having different criticalities for pattern failure by applying design rule checks on design data for the wafer surrounding locations of the defects detected on the wafer.

23. The wafer inspection tool of claim 18, wherein the binning step separates the defects that are nuisance defects into one or more first groups and the defects that are defects of interest into one or more second groups.

24. The wafer inspection tool of claim 18, wherein the binning step shapes a sample of the defects that are defects of interest by separating different types of the defects of interest into different groups.

25. The wafer inspection tool of claim 18, wherein the information further comprises flags for each of the design attributes indicating whether the design attributes are categorical attributes or measurement attributes.

26. The wafer inspection tool of claim 18, wherein the binning step separates the defects based on design data for the water surrounding locations of the defects detected on the wafer, and wherein the information further comprises flags for each of the design attributes indicating an extent of the design data used to calculate the design attributes.

27. The wafer inspection tool of claim 26, wherein the extent of the design data are an entirety of the design data or an area of interest within the design data.

28. The wafer inspection tool of claim 18, wherein the information further comprises one or more layer operators for the one or more formulae, and wherein the one or more layer operators are one or more logical operators applied to polygons of two or more layers in the design.

29. The wafer inspection tool of claim 28, wherein the one or more logical operators comprise one or more of logical AND, OR, XOR, and NOT operators.

30. The wafer inspection tool of claim 28, wherein the information further comprises one or more calculations for the one or more formulae performed on polygons resulting from the one or more logical operators, and wherein the results of the one or more calculations are the calculated design attributes.

31. The wafer inspection tool of claim 30, wherein the one or more calculations comprise one or more of counting a number of the polygons resulting from the one or more logical operators, counting a number of vertices in each of the polygons resulting from the one or more logical operators, summing an area of all of the polygons resulting from the one or more logical operators, determining a minimum area of all areas of the polygons resulting from the one or more logical operators, and determining a maximum area of all areas of the polygons resulting from the one or more logical operators.

32. The wafer inspection tool of claim 18, wherein the calculated design attributes further comprise pattern density of polygons in the design.

33. The wafer inspection tool of claim 18, wherein the wafer inspection tool is configured as a broadband plasma tool.