Inspection device and image capture element
View Patent ↗An imaging device includes multiple sensor pixels that are arranged in a predetermined direction, each sensor pixel having multiple sensor pixel borders defining an outer edge part of the sensor pixel, among which at least one of a pair of sensor pixel borders that are opposed in the arrangement direction is oblique to a passage direction of a defect image that is vertical to the predetermined direction. This can provide an inspection tool enabling high sensitivity inspection and/or having improved detection reproducibility of a defect.
1. An inspection tool, comprising:
illumination optics configured to supply inspection light to a sample to define an illumination area on the sample;
an imaging device configured to detect light from the sample; and
a processor, wherein:
the imaging device includes multiple sensor pixels that are arranged in a direction substantially vertical to a main scanning direction of the illumination area on the sample,
a pair of sensor pixel borders opposed in the pixel arrangement direction are oblique to the main scanning direction, and
the processor is configured to:
determine whether a detection signal waveform from the multiple sensor pixels includes a peak, and
acquire a position of a defect on the sample based on a detection signal waveform determined to include a peak.
2. The inspection tool according to claim 1 , wherein
the processor acquires a position of the defect based on correlation of the detection signal waveform.
3. The inspection tool according to claim 2 , wherein
the processor acquires a position of the defect in the primary scanning direction based on a sampling rate and a sampling timing when the detection signal waveform is extracted.
4. The inspection tool according to claim 3 , wherein
the processor acquires a position of the defect in a secondary scanning direction based on a center position of a defect image when the detection signal waveform is obtained.
5. The inspection tool according to claim 4 , wherein
the processor acquires a variation of the correlation and changes the position of the defect in the secondary scanning direction based on the variation.
6. The inspection tool according to claim 5 , further comprising a noise removal unit configured to remove a predetermined background noise component from an output signal of the sensor pixels and output the detection signal waveform.
7. The inspection tool according to claim 6 , wherein
the output signal has a sampling rate which is given by a predetermined driving signal that is shorter than a sampling time of the defect image.
8. The inspection tool according to claim 7 , wherein
the sensor pixels have a dimension that is substantially equal to an optical resolution of a defect to be detected.
9. The inspection tool according to claim 8 , wherein
each sensor pixel has a triangle shape.
10. The inspection tool according to claim 9 , wherein
each sensor pixel has an isosceles triangle shape.
11. The inspection tool according to claim 8 , wherein
each sensor pixel has a parallelogram shape.
12. The inspection tool according to claim 1 , wherein
the processor acquires a position of a defect in the primary scanning direction based on a sampling rate and a sampling timing when the detection signal waveform is extracted.
13. The inspection tool according to claim 1 , wherein
the processor acquires a position of a defect in a secondary scanning direction based on a center position of a defect image when the detection signal waveform is obtained.
14. The inspection tool according to claim 1 , wherein
the processor uses a variation of correlation of the detection signal waveform to change a position of a defect in a secondary scanning direction.
15. The inspection tool according to claim 1 , further comprising a noise removal unit configured to remove a predetermined background noise component from an output signal of the sensor pixels and output the detection signal waveform.
16. The inspection tool according to claim 1 , wherein an output signal of the sensor pixels has a sampling rate which is given by a predetermined driving signal that is shorter than a sampling time of a defect image.
17. The inspection tool according to claim 1 , wherein
the sensor pixels have a dimension that is substantially equal to an optical resolution of a defect to be detected.
18. The inspection tool according to claim 1 , wherein
each sensor pixel has a triangle shape.
19. The inspection tool according to claim 18 , wherein
each sensor pixel has an isosceles triangle shape.
20. The inspection tool according to claim 1 , wherein
each sensor pixel has a parallelogram shape.