Patent ID: 6928184

Claim:
A metrology instrument for measuring and inspecting deviations between a pair of pattern elements to be stitched within an image formed by electron beam lithography, said metrology instrument comprising: a means for obtaining an image of the stitched pattern for inspection, said image displaying a pair of elements of said image pattern having perpendicular edges extending in X and Y directions and being stitched to each other to align along a straight boundary line extending in the X direction; a ΔX-measuring device for measuring the deviation ΔX between stitched elements of said image pattern along said straight boundary line; a storing means for storing in computer memory sets of data defining dose distribution images of each pattern element in said pair of pattern elements indicating the dose distributions, said dose distribution images being calculated by a simulation method under the condition that a selected energetic beam is used when said pattern elements are transferred; an image superimposing means for shifting one of the dose distribution images measured by said ΔX along said straight boundary line and by a desired amount ΔY in a direction perpendicular to said straight boundary line relatively to the other and superimposing both of said dose distribution images; and an image comparator for taking the correlation between image data obtained for said inspection and said superimposed dose distribution image data by comparing these two kinds of image data.