Determination of defect location for examination of a specimen

Patent metadata

Field	Value
Publication number	US-11423529-B2
Application number	US-202016794172-A
Country	US
Kind code	B2
Filing date	Feb 18, 2020
Priority date	Feb 18, 2020
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

There is provided a method and a system configured to obtain an image of a one or more first areas of a semiconductor specimen acquired by an examination tool, determine data Datt informative of defectivity in the one or more first areas, determine one or more second areas of the semiconductor specimen for which presence of a defect is suspected based at least on an evolution of Datt, or of data correlated to Datt, in the one or more first areas, and select the one or more second areas for inspection by the examination tool.

First claim

What is claimed is:

1. A system of examination of a semiconductor specimen, the system comprising a processor and memory circuitry (PMC) configured to:
obtain an image of one or more first areas of a semiconductor specimen acquired by an examination tool;
determine data D att informative of defectivity in the one or more first areas;
determine a probability of presence of a defect in a plurality of areas of the specimen, using a probability model informative of a spatial distribution of defectivity in at least part of the specimen and data informative of the first areas comprising at least one of:
a spatial trend of data D att informative of defectivity in the one or more first areas;
a spatial trend of data correlated to D att in the one or more first areas,

wherein at least one of the plurality of areas differs from the one or more first areas;
using at least part of said probability of presence of a defect in the plurality of areas to select, among said plurality of areas of the specimen, one or more second areas of the semiconductor specimen for which presence of a defect is suspected, for inspection by the examination tool, wherein said probability of presence of a defect determined for the plurality of areas using data informative of the first areas enables selection of the one or more second areas before acquisition of an image of the one or more second areas by the examination tool.

2. The system of claim 1 , wherein determination of the one or more second areas is based on a search of an extremum of D att .

3. The system of claim 1 , configured to:
determine D correl representative of a correlation between:
data D att informative of defectivity in the one or more first areas; and
data representative of a thickness of the semiconductor specimen in the one or more first areas;

determine one or more second areas of the semiconductor specimen for which presence of a defect is suspected, wherein the one or more second areas are determined based on D correl , or data representative thereof, and data representative of a thickness of the semiconductor specimen; and
select the one or more second areas for inspection by the examination tool.

4. The system of claim 3 , wherein if data D correl includes a function F which depends on data representative of a thickness of the semiconductor specimen over a range R, the system is configured to select the second area such that at least one of (i), (ii) and (iii) is met:
(i) data representative of a thickness of the semiconductor specimen in the second area complies with the function F in the range R;
(ii) data representative of a thickness of the semiconductor specimen in the second area allows testing the function F over a range R′ different from R; and
(iii) data representative of a thickness of the semiconductor specimen in the second area is selected to attempt to move towards an extremum of an output of the function F.

5. The system of claim 3 , wherein:
at least one of data representative of a thickness of the semiconductor specimen in the one or more first areas, and data representative of a thickness of the semiconductor specimen, is obtained based on pixel intensity in an image acquired by at least one optical examination tool; or
at least one of data representative of a thickness of the semiconductor specimen in the one or more first areas and data representative of a thickness of the semiconductor specimen is obtained based on pixel intensity in a plurality of images acquired by at least one optical examination tool, wherein the plurality of images differs by a wavelength of an illuminating optical signal of the optical examination tool.

6. The system of claim 3 , wherein said determination of the one or more second areas is enabled even when an image of the one or more second areas by the examination tool is not yet available.

7. The system of claim 3 , configured to output data representative of a probability that a defect is present in one or more areas of the semiconductor specimen, or of another semiconductor specimen, based on data representative of a thickness of the semiconductor specimen, or the another semiconductor specimen, in the one or more areas, without requiring acquisition of an image of the one or more areas by the examination tool.

8. The system of claim 1 , configured to perform repeatedly (1), (2), (3) and (4), from i equal to 1, until a stopping criterion is met:
(1) obtain an image of one or more areas A i of a semiconductor specimen acquired by an examination tool;
(2) determine data D att informative of defectivity in the one or more areas A i ;
(3) determine one or more areas A i+1 of the semiconductor specimen for which presence of a defect is suspected, based at least on an evolution of D att in the one or more areas A i ; and
(4) reverting to (1) for i incremented by one.

9. The system of claim 1 , configured to perform repeatedly (1), (2), (3) and (4), from i equal to 1, until a stopping criterion is met:
(1) obtain an image of an area A i of a semiconductor specimen acquired by an examination tool;
(2) determine data D correl,i representative of a correlation between:
data D att informative of defectivity in the area A i ; and
data representative of a thickness of the semiconductor specimen in the area A i ;

(3) determine one or more areas A i+1 of the semiconductor specimen for which presence of a defect is suspected, wherein the one or more areas A i+1 are determined based at least on D correl,i , or data representative thereof, and data representative of a thickness of the semiconductor specimen; and
(4) reverting to (1) for i incremented by one.

10. The system of claim 1 , wherein the probability is based on at least one of and (i) and (ii):
(i) data D att informative of defectivity in the one or more first areas; and
(ii) data D correl representative of a correlation between data D att informative of defectivity in the one or more first areas and data representative of a thickness of the semiconductor specimen in the one or more first areas, and data representative of a thickness of the semiconductor specimen.

11. The system of claim 1 , configured to:
obtain an image of one or more first areas of a semiconductor specimen acquired by an examination tool;
determine data Datt informative of defectivity in the one or more first areas;
determine a probability of presence of a defect in a plurality of areas of the specimen, using a probability model, a model of the specimen and at least one of:
an evolution of data Datt informative of defectivity in the one or more first areas; and
an evolution of data correlated to Datt in the one or more first areas;

wherein at least one of the plurality of areas differs from the one or more first areas,
determine, among said plurality of areas of the specimen, one or more second areas for which presence of a defect is suspected;
select the one or more second areas for inspection by the examination tool; and
determine presence of defects within the one or more second areas and use said determination to update the model of the specimen.

12. The system of claim 1 , configured to select the one or more first areas based on a first probability map representing probability of a presence of defects over the semiconductor specimen, wherein the first probability map is built based on at least one of:
an image of the semiconductor specimen acquired by an optical examination tool;
estimation of defect location based on an image of the semiconductor specimen acquired by an optical examination tool;
historical data regarding defect location;
an image of the semiconductor specimen acquired

Assignees

• Applied Materials Israel Ltd
• Applied Mat Isreal Ltd

Inventors

• Girmonsky Doron
• Ben Ami Rafael
• Cohen Boaz
• Shemesh Dror

Classifications

• Y02P90/02

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