Misalignment measuring apparatus and misalignment measuring method
AssigneeKioxia Corporation
InventorsYuki Watanabe, Kazuhiro Nojima
Life of this patent
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Abstract
According to one embodiment, a misalignment measuring apparatus includes: an input circuit; a storage medium; a first circuit configured to, in a first calibration pattern, calculate a second misalignment amount; a second circuit configured to, using a first image of a second calibration pattern, calculate a third misalignment amount; a third circuit configured to calculate a coefficient indicating; and a fourth circuit configured to, using a second image corresponding to the first and second patterns, calculate a third center position of a third contour and calculate the first misalignment amount between the first pattern and the second pattern based on the fourth misalignment amount and the coefficient.
Claims16
A misalignment measuring apparatus that measures a first misalignment amount between a first pattern and a second pattern formed on the first pattern, the misalignment measuring apparatus comprising:
- an input circuit configured to receive an image;
- a storage medium configured to store the image;
- a first circuit configured to, in a first calibration pattern including a third pattern corresponding to the first pattern and a fourth pattern formed on the third pattern, calculate a second misalignment amount between the third pattern and the fourth pattern;
- a second circuit configured to, using a first image of a second calibration pattern including a fifth pattern corresponding to the first pattern and a sixth pattern formed on the fifth pattern and corresponding to the second pattern, calculate a first center position of a first contour based on a first threshold corresponding to the fifth pattern and a second center position of a second contour based on a second threshold corresponding to the fifth pattern, and calculate a third misalignment amount between the first center position and the second center position;
- a third circuit configured to calculate a coefficient indicating a relation between the second misalignment amount and the third misalignment amount;
- and
- a fourth circuit configured to, using a second image corresponding to the first and second patterns, calculate a third center position of a third contour based on a third threshold corresponding to the first pattern and a fourth center position of a fourth contour based on a fourth threshold corresponding to the first pattern, calculate a fourth misalignment amount between the third center position and the fourth center position, and calculate the first misalignment amount between the first pattern and the second pattern based on the fourth misalignment amount and the coefficient.
A misalignment measuring method for measuring a first misalignment amount between a first pattern and a second pattern formed on the first pattern, the misalignment measuring method comprising:
- in a first calibration pattern including a third pattern corresponding to the first pattern and a fourth pattern formed on the third pattern, calculating a second misalignment amount between the third pattern and the fourth pattern;
- acquiring a first image of a second calibration pattern including a fifth pattern corresponding to the first pattern and a sixth pattern formed on the fifth pattern and corresponding to the second pattern;
- using the first image, calculating a first center position of a first contour based on a first threshold corresponding to the fifth pattern and a second center position of a second contour based on a second threshold corresponding to the fifth pattern;
- calculating a third misalignment amount between the first center position and the second center position;
- calculating a coefficient indicating a relation between the second misalignment amount and the third misalignment amount;
- acquiring a second image corresponding to the first and second patterns;
- using the second image, calculating a third center position of a third contour based on a third threshold corresponding to the first pattern and a fourth center position of a fourth contour based on a fourth threshold corresponding to the first pattern;
- calculating a fourth misalignment amount between the third center position and the fourth center position;
- and
- calculating the first misalignment amount between the first pattern and the second pattern based on the fourth misalignment amount and the coefficient.
Dependencies are inferred from the claim text.