Patent ID: 8507858

Claim:
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.