Dynamic Binning for Diversification and Defect Discovery

Patent metadata

Field	Value
Publication number	US-2016110857-A1
Application number	US-201514614202-A
Country	US
Kind code	A1
Filing date	Feb 4, 2015
Priority date	Oct 19, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

Methods and systems for generating a defect sample for a wafer are provided. One method includes separating defects detected on a wafer into bins having diversity in values of a first set of one or more first attributes of the defects. The method also includes selecting, independently from one or more of the bins, defects within the bins based on diversity in a second set of one or more second attributes of the defects. The selected defects are then used to create a defect sample for the wafer. In this manner, defects having diverse values of multiple attributes can be easily selected.

First claim

What is claimed is:

1 . A computer-implemented method for generating a defect sample for a wafer, comprising:
acquiring inspection results for the wafer, wherein the inspection results comprise information for defects detected on the wafer by an inspection process, and wherein the information comprises information for at least a first set of one or more first attributes for the defects and a second set of one or more second attributes for the defects; identifying values of the one or more first attributes having the most diversity in the values of the one or more first attributes; generating a set of bins for the defects based on the identified values such that each of the bins corresponds to only a portion of the values and such that the values corresponding to the bins have diversity in the one or more first attributes; separating the defects into the bins based on the values of the one or more first attributes corresponding to the defects; selecting, from one of the bins, defects within the one of the bins based on diversity in values of the one or more second attributes; repeating said selecting for at least one other of the bins; and creating a defect sample for the wafer comprising the defects selected from the one of the bins and the at least one other of the bins, wherein said acquiring, said identifying, said generating, said separating, said selecting, said repeating, and said creating are performed by a computer system.

2 . The method of claim 1 , wherein the one or more first attributes comprise one or more attributes of background of the defects on the wafer.

3 . The method of claim 1 , wherein the one or more second attributes comprise one or more characteristics of a signal detected for the defects in the inspection process.

4 . The method of claim 1 , wherein the wafer has unknown defectivity.

5 . The method of claim 1 , wherein the one or more first attributes and a number of the bins included in the set are selected by a user.

6 . The method of claim 1 , further comprising determining one or more characteristics of the bins based on the defects separated into the bins, displaying the one or more characteristics to a user prior to said selecting, and requesting from the user a validation of the one or more characteristics.

7 . The method of claim 1 , further comprising determining one or more characteristics of the defects selected from the bins, displaying the one or more characteristics to a user prior to said creating, and requesting from the user a validation of the one or more characteristics.

8 . The method of claim 1 , further comprising determining a first characteristic of the bins based on the defects separated into the bins, determining a second characteristic of the defects selected from the bins, wherein the first characteristic is not the same as the second characteristic, displaying the first and second characteristics to a user prior to said creating, and requesting from the user a validation of the first and second characteristics.

9 . The method of claim 1 , wherein said selecting is performed based on the diversity such that the defects selected from the one of the bins have the most diversity in the values of the one or more second attributes.

10 . The method of claim 1 , wherein said selecting is performed based on the diversity and one or more sample biasing parameters.

11 . The method of claim 1 , further comprising separately selecting, from the one of the bins, defects within the one of the bins based on diversity in values of one or more third attributes of the defects, further comprising repeating said separately selecting for the at least one other of the bins, and wherein creating the defect sample comprises adding the defects separately selected from the one of the bins and the at least one other of the bins to the defect sample.

12 . The method of claim 1 , further comprising generating a set of sub-bins for a bin from which the defects were selected based on the values of the one or more second attributes such that each of the sub-bins corresponds to only a portion of the values of the one or more second attributes and such that the values of the one or more second attributes corresponding to the sub-bins have diversity in the one or more second attributes.

13 . The method of claim 12 , further comprising separately selecting, from one of the sub-bins, defects within the one of the sub-bins based on diversity in values of one or more third attributes of the defects, further comprising repeating said separately selecting for at least one other of the sub-bins, and wherein creating the defect sample comprises adding the defects separately selected from the one of the sub-bins and the at least one other of the sub-bins to the defect sample.

14 . The method of claim 1 , wherein the same number of defects are selected from each of the bins from which defects are selected.

15 . The method of claim 1 , wherein said selecting is performed independently for each of the bins from which defects are selected.

16 . The method of claim 1 , wherein said generating comprises sampling at least one of the defects having each of the identified values from the inspection results and defining the bins based on the sampled at least one of the defects having each of the identified values.

17 . The method of claim 1 , further comprising storing information for the bins into which the defects are separated as a bin attribute for each of the defects that is separated into a bin, wherein said selecting and said repeating are performed based on the bin attributes of the defects.

18 . The method of claim 1 , wherein the method and said generating do not comprise tuning cutlines separating the bins from each other.

19 . The method of claim 1 , wherein the method is performed for one or more other wafers, and wherein the set of bins generated for the wafer is not used as a set of bins for the one or more other wafers.

20 . A non-transitory computer-readable medium, storing program instructions executable on a computer system for performing a computer-implemented method for generating a defect sample for a wafer, wherein the computer-implemented method comprises:
acquiring inspection results for the wafer, wherein the inspection results comprise information for defects detected on the wafer by an inspection process, and wherein the information comprises information for at least a first set of one or more first attributes for the defects and a second set of one or more second attributes for the defects; identifying values of the one or more first attributes having the most diversity in the values of the one or more first attributes; generating a set of bins for the defects based on the identified values such that each of the bins corresponds to only a portion of the values and such that the values corresponding to the bins have diversity in the one or more first attributes; separating the defects into the bins based on the values of the one or more first attributes corresponding to the defects; selecting, from one of the bins, defects within the one of the bins based on diversity in values of the one or more second attributes; repeating said selecting for at least one other of the bins; and creating a defect sample for the wafer comprising the defects selected from the one of the bins and the at least one other of the bins.

21 . A system configured to generate a defect sample for a wafer, comprising:
an inspection subsystem configured to

Assignees

• Kla Tencor Corp

Inventors

• Plihal Martin
• Anantha Vidyasagar

Classifications

• G01N21/8851 Primary

  Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges (G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002) · CPC title

• G06V10/772

  Determining representative reference patterns, e.g. averaging or distorting patterns; Generating dictionaries · CPC title

• G06T7/0004 Primary

  Industrial image inspection · CPC title

• G06F18/28

  Determining representative reference patterns, e.g. by averaging or distorting; Generating dictionaries · CPC title

• G01N2021/8854

  Grading and classifying of flaws · CPC title