Pattern measurement apparatus and pattern measurement method
AssigneeAdvantest Corporation
InventorsHiroshi Fukaya, Yoshiaki Ogiso
Life of this patent
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Abstract
Referring to design data for a sample, a measurement region is defined at a portion in the design data which has no step in an edge of a pattern. In addition, an edge as a characteristic portion is detected from the design data, and an edge as a characteristic portion corresponding to the characteristic portion of the design data is detected from a secondary electron image. Then, the measurement region is positioned and located in a secondary electron image based on a positional relationship between the edge of the design data and the edge of the secondary electron image. A width of the pattern is measured on the basis of a distance between the two edges included in the measurement region thus located.
Claims16
A pattern measurement apparatus comprising:
- an electron beam irradiation unit configured to irradiate a surface of a sample with an electron beam;
- a detector configured to detect secondary electrons generated on the surface of the sample;
- a signal processor configured to create a secondary electron image of the surface of the sample based on a detection signal from the detector;
- a measurement region definition unit configured to define a measurement region in design data while referring to the design data for the sample;
- a first detection unit configured to detect a characteristic portion of the design data;
- a second detection unit configured to detect a characteristic portion of the secondary electron image;
- an alignment unit configured to position and locate the measurement region of the design data in the secondary electron image based on a positional relationship between the characteristic portion of the design data and the characteristic portion of the secondary electron image;
- and
- a measurement unit configured to measure a width of a pattern based on positions of edges of the pattern inside the measurement region of the secondary electron image.
A pattern measurement method for defining a measurement region in a secondary electron image and finding a line width of a pattern in the measurement region using positions of edges of the pattern, the method comprising the steps of:
- defining a measurement region in design data corresponding to a field of view of the secondary electron image;
- detecting a characteristic portion of the design data;
- detecting a characteristic portion of the secondary electron image;
- and
- positioning and locating the measurement region of the design data in the secondary electron image based on a positional relationship between the characteristic portion of the design data and the characteristic portion of the secondary electron image.
Dependencies are inferred from the claim text.