Pattern inspection apparatus and pattern inspection method

1. An inspection apparatus comprising:

a stage on which an inspection target object with a plurality of figure patterns formed thereon is placed and which is movable;

a light source that emits an inspection light;

a sensor that captures an optical image of the plurality of figure patterns formed on the inspection target object by using the inspection light while moving relatively to the stage; and

processing circuitry configured to:

virtually divide a whole of an inspection region of the inspection target object into stripe regions, each of the stripe regions including a corresponding one of a plurality of discrete small regions, and each of the stripe regions and the plurality of discrete small regions having a same width as a width of the whole of the inspection region;

perform a pre-scan such that the pre-scan is completed before being affected by a temperature change in the inspection apparatus, by controlling to acquire an optical image in each of the plurality of discrete small regions in order, while relatively moving the sensor and the stage without performing imaging with respect to a region located between each of the plurality of discrete small regions;

perform a full-scan by controlling to acquire an optical image in each of the stripe regions in the whole of the inspection region of the inspection target object in order while relatively moving the sensor and the stage;

calculate a first positional deviation amount between a dimension of a figure in each optical image acquired when capturing images of the plurality of discrete small regions in relation to the pre-scan and a dimension of a figure in a reference image corresponding to the each optical image;

generate a first positional deviation amount map of the whole of the inspection region by using the first positional deviation amount of each of the plurality of discrete small regions;

calculate a second positional deviation amount between a dimension of a figure in each optical image acquired when capturing images of the whole of the inspection region in relation to the full-scan and a dimension of a figure in a reference image corresponding to the each optical image;

generate a second positional deviation amount map of the whole of the inspection region by using the second positional deviation amount;

generate a first positional deviation difference map by calculating a difference between the first positional deviation amount map and the second positional deviation amount map;

generate a third positional deviation amount map by calculating a difference between the second positional deviation amount map and the first positional deviation difference map, the third positional deviation amount map corresponding to a corrected positional deviation amount man that compensates for the temperature change;

judge existence of a value exceeding an allowable value, in values defined by the third positional deviation amount map; and

output a judgment result to indicate whether a mask is allowable, wherein

the plurality of discrete small regions are disposed apart from each other at a particular distance to suppress bias of the inspection region, and are provided within the stripe regions; and

an area of one of the plurality of discrete small regions is less than an area of the region that is located between two consecutive discrete small regions from among the plurality of discrete small regions.

2. The apparatus according to claim 1 , wherein the processing circuitry is further configured to:

calculate a first dimension error amount between the dimension of the figure in the each optical image acquired when capturing images of the plurality of discrete small regions in relation to the pre-scan and the dimension of the figure in the reference image corresponding to the each optical image;

generate a first dimension error amount map of the whole of the inspection region by using the first dimension error amount of each of the plurality of discrete small regions;

calculate a second dimension error amount between the dimension of the figure in the each optical image acquired when capturing images of the whole of the inspection region in relation to the full-scan and the dimension of the figure in the reference image corresponding to the each optical image;

generate a second dimension error amount map of the whole of the inspection region by using the second dimension error amount;

generate a first dimension error difference map by calculating a difference between the first dimension error amount map and the second dimension error amount map;

generate a third dimension error amount map by calculating a difference between the second dimension error amount map and the first dimension error difference map; and

judge existence of a value exceeding an allowable value, in values defined by the third dimension error amount map.

3. The apparatus according to claim 2 , wherein the processing circuitry is further configured to output a judgment result with respect to a dimension error amount.

4. The apparatus according to claim 1 , wherein the stripe regions extend in a predetermined direction.

5. The apparatus according to claim 1 , wherein:

the processing circuitry is further configured to:

judge whether a figure pattern exists in each of the stripe regions, and

when a figure pattern exists in each of all of judged stripe regions, set the all of the judged stripe regions, as the plurality of discrete small regions, and, when a figure pattern does not exist in each of some or all of the judged stripe regions, set stripe regions each including a figure pattern and stripe regions each inducing a figure pattern, being closest to a stripe region including no figure pattern, and serving instead of the stripe region including no figure pattern, as the plurality of discrete small regions.

6. A pattern inspection method for an inspection apparatus including a sensor and a stage, the pattern inspection method comprising:

virtually dividing a whole of an inspection region of an inspection target object into stripe regions, each of the stripe regions including a corresponding one of a plurality of discrete small regions, and each of the stripe regions and the plurality of discrete small regions having a same width as a width of the whole of the inspection region;

performing a pre-scan such that the pre-scan is completed before being affected by a temperature change in the inspection apparatus, by controlling to acquire an optical image in each of the plurality of discrete small regions in order, while relatively moving the sensor and the stage without performing imaging with respect to a region located between each of the plurality of discrete small regions;

performing a full-scan by controlling to acquire an optical image in each small region of the stripe regions in the whole of the inspection region of the inspection target object in order while relatively moving the sensor and the stage;

calculating a first positional deviation amount between a dimension of a figure in each optical image acquired when capturing images of the plurality of discrete small regions in relation to the pre-scan and a dimension of a figure in a reference image corresponding to the each optical image;

generating a first positional deviation amount map of the whole of the inspection region by using the first positional deviation amount of each of the plurality of discrete small regions;

generating a second positional deviation amount map by using data acquired by the full-scan;

generating a first positional deviation difference map by calculating a difference between the first positional deviation amount map and the second positional deviation amount map;

generating a third positional deviation amount map from the first positional deviation difference map and the second positional deviation amount map, the third positional deviation amount map corresponding to a corrected positional deviation amount map that compensates for the temperature change;

judging existence of a value exceeding an allowable value, in values defined by the third positional deviation amount map; and

outputting a judgement result to indicate whether a mask is allowable, wherein

the plurality of discrete small regions are disposed apart from each other at a particular distance to suppress bias of the inspection region, and are provided within the stripe regions; and

an area of one of the plurality of discrete small regions is less than an area of the region that is located between two consecutive discrete small regions from among the plurality of discrete small regions.

7. The method according to claim 6 , wherein, in the second positional deviation amount map, there is defined a second positional deviation amount between a dimension of a figure in each optical image acquired when capturing images of the whole of the inspection region in relation to the full-scan and a dimension of a figure in a reference image corresponding to the each optical image.

8. The method according to claim 6 , further comprising:

generating a first dimension error amount map by using data acquired by the pre-scan;

generating a second dimension error amount map by using data acquired by the full-scan;

generating a first dimension error amount difference map by calculating a difference between the first dimension error amount map and the second dimension error amount map;

generating a third dimension error amount map from the first dimension error amount difference map and the second dimension error amount map; and

judging existence of a value exceeding an allowable value, in values defined by the third dimension error amount map.

9. The method according to claim 8 , wherein, in the first dimension error amount map, there is defined a first dimension error amount between the dimension of the figure in the each optical image acquired when capturing images of the plurality of discrete small regions and the dimension of the figure in the reference image corresponding to the each optical image.

10. The method according to claim 8 , wherein, in the second dimension error amount map, there is defined a second dimension error amount between the dimension of the figure in the each optical image acquired when capturing images of the whole of the inspection region and the dimension of the figure in the reference image corresponding to the each optical image.

11. The method according to claim 9 , wherein the stripe regions extend in a predetermined direction.

12. The method according to claim 9 , further comprising:

judging whether a figure pattern exists in each of the stripe regions; and

setting, when a figure pattern exists in each of all of judged stripe regions, the all of the judged stripe regions, as the plurality of discrete small regions, and, when a figure pattern does not exist in each of some or all of the judged stripe regions, stripe regions each including a figure pattern and stripe regions each including a figure pattern, being closest to a stripe region including no figure pattern, and serving instead of the stripe region including no figure pattern, as the plurality of discrete small regions.

13. The method according to claim 9 , further comprising:

calculating a first positional deviation amount between the dimension of the figure in the each optical image acquired when capturing images of the plurality of discrete small regions and the dimension of the figure in the reference image corresponding to the each optical image;

calculating a second positional deviation amount between the dimension of the figure in the each optical image acquired when capturing images of the whole of the inspection region and the dimension of the figure in the reference image corresponding to the each optical image; and

outputting a judgment result with respect to a dimension error amount.

14. A pattern inspection method for an inspection apparatus including a sensor and a stage, the pattern inspection method comprising:

virtually dividing a whole of an inspection region of the inspection target object into stripe regions, each of the stripe regions including a corresponding one of a plurality of discrete small regions, and each of the stripe regions and the plurality of discrete small regions having a same width as a width of the whole of inspection region;

performing a pre-scan such that the pre-scan is completed before being affected by a temperature change in the inspection apparatus, by controlling to acquire an optical image in each of the plurality of discrete small regions in order, while relatively moving the sensor and the stage without performing imaging with respect to a region located between each of the plurality of discrete small regions;

performing a full-scan by controlling to acquire an optical image in each of the stripe regions in the whole of the inspection region of the inspection target object in order while relatively moving the sensor and the stage;

generating a first dimension error amount map by using data acquired by the pre-scan;

generating a second dimension error amount map by using data acquired by the full-scan;

generating a first dimension error amount difference map by calculating a difference between the first dimension error amount map and the second dimension error amount map;

generating a third dimension error amount map from the first dimension error amount difference map and the second dimension error amount map, the third dimension error amount map corresponding to a corrected dimension error amount map that compensates for the temperature change;

judging existence of a value exceeding an allowable value, in values defined by the third dimension error amount map; and

outputting a judgment result to indicate whether a mask is allowable, wherein

the plurality of discrete small regions are disposed apart from each other at a particular distance to suppress bias of the inspection region, and are provided within the stripe regions; and

an area of one of the plurality of discrete small regions is less than an area of the region that is located between two consecutive discrete small regions from among the plurality of discrete small regions.

15. The method according to claim 14 , wherein, in the first dimension error amount map, there is defined a first dimension error amount between a dimension of a figure in each optical image acquired when capturing images of the plurality of discrete small regions and a dimension of a figure in a reference image corresponding to the each optical image.

16. The method according to claim 14 , wherein, in the second dimension error amount map, there is defined a second dimension error amount between a dimension of a figure in each optical image acquired when capturing images of the whole of the inspection region and a dimension of a figure in a reference image corresponding to the each optical image.

17. The method according to claim 14 , wherein the plurality of stripe regions extend in a predetermined direction.

18. The method according to claim 14 , further comprising:

judging whether a figure pattern exists in each of the stripe regions; and

setting, when a figure pattern exists in each of all of judged stripe regions, the all of the judged stripe regions, as a plurality of discrete small regions, and, when a figure pattern does not exist in each of some or all of the judged stripe regions, stripe regions each including a figure pattern and stripe regions each including a figure pattern, being closest to a stripe region including no figure pattern, and serving instead of the stripe region including no figure pattern, as the plurality of discrete small regions.

19. The apparatus according to claim 1 , wherein

the processing circuitry is further configured to determine, from the plurality of discrete small regions, a pre-scan region to be pre-scanned.

20. The apparatus according to claim 1 , wherein

a total imaging time of the pre-scan is less than a total imaging time of the full-scan.