Pattern inspection apparatus and method
A fine pattern, such as a semiconductor integrated circuit (LSI), a liquid crystal panel, and a photomask (reticle) for the semiconductor or the liquid crystal panel, which are fabricated based on data for fabricating the fine pattern such as design data is inspected by a pattern inspection apparatus. The pattern inspection apparatus for inspecting a pattern to-be-inspected uses an image of the pattern to-be-inspected and data for fabricating the pattern to-be-inspected. The pattern inspection apparatus includes a reference pattern generation device configured to generate a reference pattern represented by one or more lines from the data, an image generation device configured to generate the image of the pattern to-be-inspected, a detecting device configured to detect an edge of the image of the pattern to-be-inspected, and an inspection device configured to inspect the pattern to-be-inspected by comparing edges of the image of the pattern to-be-inspected with the one or more lines of the reference pattern.
1. A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising:
an image generation device configured to generate said image of said pattern to-be-inspected; and
a memory storing a plurality of machine readable instructions that when executed perform the steps of:
(a) storing in said memory a reference pattern generated from said data, said reference pattern represented by one or both of (i) one or more line segments, and (ii) one or more curves, said reference pattern generated from said data;
(b) storing in said memory detected edges of said image; and
(c) inspecting said pattern to-be-inspected by using at least one of distances between said detected edges and at least one of said line segments and said curves of said reference pattern to generate defect information,
wherein said machine readable instructions, when executed, detect at least one edge of said image by:
(i) setting a profile acquisition section by using at least one of said line segments and said curves of said reference pattern,
(ii) obtaining a profile of said image of said pattern-to-be-inspected by using said profile acquisition section and said image of said pattern to-be-inspected, and
(iii) detecting said edge from said profile of said image of said pattern to-be-inspected.
2. The pattern inspection apparatus according to claim 1 , wherein said profile includes a plurality of points determined by interpolation of luminance between pixels of the image, and wherein detecting edges from said profile is performed by thresholding interpolated points.
3. The pattern inspection apparatus according to claim 1 , wherein said machine readable instructions, when executed, construct an area from said edges of said image of said pattern to-be-inspected which fail to correspond to edges of said reference pattern, and recognize said area as a defective area.
4. The pattern inspection apparatus according to claim 1 , wherein said machine readable instructions, when executed, calculate a pattern deformation quantity of said pattern to-be-inspected from a relationship of said detected edge of said image of said pattern to-be-inspected and edges obtained by converting said reference pattern, that have been determined to be in the correspondence to each other.
5. A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising:
an image generation device configured to generate said image of said pattern to-be-inspected; and
a memory storing a plurality of machine readable instructions that when executed perform the steps of:
(a) storing in said memory a reference pattern generated from said data, said reference pattern represented by one or both of (i) one or more line segments, and (ii) one or more curves, said reference pattern generated from said data;
(b) storing in said memory detected edges of said image;
(c) inspecting said pattern to-be-inspected by comparing said detected edge with at least one of said line segment and said curve of said reference pattern to generate defect information;
(d) setting a profile acquisition section by using at least one of said line segment and said curve of said reference pattern;
(e) obtaining a profile by using said profile acquisition section and said image of said pattern to-be-inspected; and
(f) detecting said edge from said profile.
6. The pattern inspection apparatus according to claim 5 , wherein said profile includes a plurality of points determined by interpolation of luminance between pixels of the image, and wherein detecting edges from said profile is performed by thresholding interpolated points.
7. A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising:
an image generation device configured to generate said image of said pattern to-be-inspected; and
a memory storing a plurality of machine readable instructions that when executed perform the steps of:
(a) storing in said memory a reference pattern generated from said data, said reference pattern represented by edge vectors;
(b)storing in said memory detected edge vectors of said image, said detected edge vectors of said image detected from said image by using at least one of a zero crossing of the second derivative of the image and a zero crossing of the first derivative of the image; and
(c) inspecting said pattern to-be-inspected by comparing said edge vectors of said image with said edge vectors of said reference pattern to generate defect information.
8. A pattern matching apparatus for matching a pattern by using an image of said pattern and data for fabricating said pattern, said pattern matching apparatus comprising:
an image generation device configured to generate said image of said pattern; and
a memory storing a plurality of machine readable instructions that when executed perform the steps of:
(a) storing in said memory a reference pattern generated from said data, said reference pattern represented by edge vectors;
(b) storing in said memory detected edge vectors of said image, said edge vectors of said image detected from said image by using at least one of a zero crossing of the second derivative of the image and a zero crossing of the first derivative of the image; and
(c) matching features of said image and said reference pattern by using at least one of said edge vectors of said image of said pattern to-be-inspected and at least one of said edge vectors of said reference pattern.
9. The pattern inspection apparatus according to claim 8 , wherein said matching is conducted by dilating at least one of said edge vectors of said image of said pattern to-be-inspected and said edge vectors of said reference pattern.
10. The pattern inspection apparatus according to claim 8 , wherein said matching is conducted by using a total sum of products of amplitudes of said edge vectors of said image of said pattern to-be-inspected and amplitudes of said edge vectors of said reference pattern, at respective pixels as an evaluation value.
11. The pattern inspection apparatus according to claim 8 , wherein said matching is conducted by using a total sum of inner products of said edge vectors of said image of said pattern to-be-inspected and said edge vectors of said reference pattern, at respective pixels or a total sum of absolute values of said inner products as an evaluation value.
12. The pattern inspection apparatus according to claim 8 , wherein said matching is conducted by altering a contribution of each part of said reference pattern to said matching.
13. The pattern inspection apparatus according to claim 7 , wherein said machine readable instructions, when executed, determine correspondence between said edge vectors of said reference pattern and said edge vectors of said image of said pattern to-be-inspected.
14. The pattern inspection apparatus according to claim 13 , wherein said correspondence is determined by considering a distance between each of said edge vectors of said reference pattern and each of said edge vectors of said image of said pattern to-be-inspected.
15. The pattern inspection apparatus according to claim 13 , wherein said machine readable instructions, when executed, construct an area from said edge vectors of said image of said pattern to-be-inspected which fail to correspond to said edge vectors of said reference pattern, and recognize said area as a defective area.
16. The pattern inspection apparatus according to claim 15 , wherein said machine readable instructions, when executed, judge a defect class based on geometrical feature quantities of said defective area.
17. The pattern inspection apparatus according to claim 15 , wherein said machine readable instructions, when executed, judge a defect class based on a feature quantity concerning a luminance of said defective area.
18. The pattern inspection apparatus according to claim 13 , wherein said machine readable instructions, when executed, construct areas from said edge vectors of said image of said pattern to-be-inspected which correspond to said edge vectors of said reference pattern, detect an area whose luminance distribution is non-uniform among said areas, and recognize said area as a defective area.
19. The pattern inspection apparatus according to claim 18 , wherein said machine readable instructions, when executed, judge a defect class based on geometrical feature quantities of said defective area.
20. The pattern inspection apparatus according to claim 18 , wherein said machine readable instructions, when executed, judge a defect class based on a feature quantity concerning a luminance of said defective area.
21. The pattern inspection apparatus according to claim 13 , wherein said machine readable instruction, when executed, calculate a pattern deformation quantity of said pattern to-be-inspected from a relation of said edge vectors of said reference pattern and said edge vectors of said image of said pattern to-be-inspected, that have been determined to correspond to each other.
22. The pattern inspection apparatus according to claim 21 , wherein said pattern deformation quantity includes at least one of a displacement quantity, a magnification variation quantity, and a dilation quantity of a line width.
23. The pattern inspection apparatus according to claim 21 , wherein said machine readable instructions, when executed, add an attribute to said reference pattern.
24. The pattern inspection apparatus according to claim 7 , wherein said machine readable instructions, when executed, set a profile acquisition section by using at least one of said edge vectors of said reference pattern, obtain a profile by using said profile acquisition section and said image of said pattern to-be-inspected, and detect said edge vectors of said image of said pattern to-be-inspected from said profile.
25. A method of inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said method comprising:
generating a reference pattern from said data, said reference pattern represented by edge vectors;
generating said image of said pattern to-be-inspected;
detecting edge vectors of said image of said pattern to-be-inspected, said detected edge vectors of said image detected from said image by using at least one of a zero crossing of the second derivative of the image and a zero crossing of the first derivative of the image; and
inspecting said pattern to-be-inspected by comparing said edge vectors of said image with said edge vectors of said reference pattern to generate defect information.
26. A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising:
an image generation device configured to generate said image of said pattern to-be-inspected; and
a memory storing a plurality of machine readable instructions that when executed perform the steps of:
(a) storing in said memory a reference pattern generated from said data, said reference pattern obtained from simulation of fabrication process using said data and represented by edge vectors;
(b) storing in said memory detected edge vectors of said image, said detected edge vectors of said image detected from said image by using at least one of a zero crossing of the second derivative of the image and a zero crossing of the first derivative of the image; and
(c) inspecting said pattern to-be-inspected by comparing said edge vectors of said image with said edge vectors of said reference pattern to generate defect information.
27. A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising:
an image generation device configured to generate said image of said pattern to-be-inspected; and
a memory storing a plurality of machine readable instructions that when executed perform the steps of:
(a) storing in said memory a reference pattern generated from said data, said reference pattern represented by edge vectors;
(b) storing in said memory detected edge vectors of said image; and
(c) inspecting said pattern to-be-inspected by comparing said edge vectors of said image with said edge vectors of said reference pattern to generate defect information;
wherein said machine readable instructions, when executed, set a profile acquisition section by using at least one of said edge vectors of said reference pattern, obtain a profile by using said profile acquisition section and said image of said pattern to-be-inspected, and detect said edge vectors of said image of said pattern to-be-inspected from said profile.