摘要:
In a pattern inspection apparatus (1), an electron beam emission part (31) emits an electron beam onto a substrate (9) and an image acquisition part (33) detects electrons from the substrate (9) to acquire a grayscale inspection image of the substrate (9). A binary reference image generated from design data (81) is multivalued by a grayscale image generator (52) on the basis of a histogram of pixel values in the inspection image to generate a grayscale reference image. A comparator (53) compares the inspection image with the reference image. The pattern inspection apparatus (1) can thereby perform an inspection of a very small pattern on the substrate (9) on the basis of the design data (81).
摘要:
A reference image and an inspection image indicating pattern on a substrate are acquired and a specified pixel value range (63) is set on the basis of a histogram (62a) of pixel values of the reference image. Then, a transfer curve (71) having a large inclination in the specified pixel value range (63) is obtained. The inspection image and the reference image are converted in accordance with an LUT having transfer characteristics indicated by the transfer curve (71), an enhanced differential image between a converted inspection image and a converted reference image is generated and each pixel value of the enhanced differential image is compared with a predetermined threshold value, to thereby perform a detection of defective pixel. With this, a value of pixel in the enhanced differential image which corresponds to a pixel in the reference image (or inspection image) having the pixel value in the specified pixel value range (63) is enhanced, and appropriate inspection is thereby performed.
摘要:
In a defect detection apparatus, images of first to third inspection areas on a substrate are picked up to acquire first to third images. A positional difference acquisition part (51) acquires a first difference vector between the first image and the second image and a second difference vector between the second image and the third image. A differential image generation part (52) generates a first differential image between the first image and the second image while adjusting a position of the first image to the second image on the basis of the first difference vector and a second differential image between the second image and the third image while adjusting a position of the second image to the third image on the basis of the second difference vector. Then, a position of the second differential image is adjusted to the first differential image on the basis of the second difference vector and the second differential image after position adjustment and the first differential image are compared with each other, to detect a defect in a periodic pattern on the substrate with high accuracy.
摘要:
In a defect detection apparatus, images of first to third inspection areas on a substrate are picked up to acquire first to third images. A positional difference acquisition part (51) acquires a first difference vector between the first image and the second image and a second difference vector between the second image and the third image. A differential image generation part (52) generates a first differential image between the first image and the second image while adjusting a position of the first image to the second image on the basis of the first difference vector and a second differential image between the second image and the third image while adjusting a position of the second image to the third image on the basis of the second difference vector. Then, a position of the second differential image is adjusted to the first differential image on the basis of the second difference vector and the second differential image after position adjustment and the first differential image are compared with each other, to detect a defect in a periodic pattern on the substrate with high accuracy.
摘要:
In a defect detection apparatus 1, in a reference image inspection circuit 42 compared are a reference image representing a pattern in a die which is determined as a reference on a substrate 9 and a plurality of supervisory images which represent patterns in selected block areas, respectively, to detect defects included in the reference image. Subsequently, in the target image inspection circuit 44, a target image representing a pattern in another die and the reference image are compared to detect a plurality of defect candidates included in the target image. Then, a defect detector 45 excludes defect candidates overlapping with the defects included in the reference image from the plurality of defect candidates on the basis of at least positional information of the defects included in the reference image. This makes it possible to detect defects existing in the pattern in another die accurately while eliminating effects of the defects existing in the pattern in the die which is determined as the reference.
摘要:
In a defect detection apparatus (1) acquired is two-dimensional image data of a swath which is a strip-like area corresponding to one of a plurality of divided patterns which are obtained by dividing a pattern block on one die of a substrate (9). In the defect detection apparatus (1), a reference image acquired from one swath in a reference die is stored in an image memory (51) and the reference image is compared with an inspection image acquired from a swath corresponding to a reference image on an inspection die by a defect detector (52) to detect defects of the inspection image. As a result, it is possible to easily achieve a defect detection of a fine pattern formed on a swath of the inspection die while reducing storage capacity required for the image memory (51).
摘要:
A marginal distribution feature extraction unit 20 sequentially focuses on each pixel in a reference image and the corresponding pixel in an inspection image, and computes a marginal distribution feature value indicative of the spatial variation in pixel values in the focus pixel neighborhood in both images. Based on this marginal distribution feature value, a tolerance image generation selection unit 26 sets a tolerance range for the reference image or inspection image focus pixel with the less spatial variation. A target image selection unit 30 selects the image comprising pixels from both images for which a tolerance range is not set as a target image. Referencing the set tolerance ranges, a comparison operator 34 compares each pixel in the target image and tolerance image, and outputs a difference Sub representing how far the pixel values of the target image are from the respective tolerance range. A defect determination circuit 38 then outputs data indicating the pixels corresponding to a defect based on a difference map containing these difference Sub values.