Method and apparatus for detecting edge of fine pattern on specimen

摘要

In a method and apparatus for detecting the edge of a fine pattern formed on a specimen such as a fine circuit pattern formed on a semiconductor element or the like, there is prepared a predetermined model waveform based on theoretical secondary electron emission from the edge portion. Secondary electrons emitted from successive scanning points across the pattern edge portion through the irradiation of a scanning electron beam thereonto are detected to produce an actual signal waveform reflecting the secondary electron emission from the pattern edge portion. The actual signal waveform is compared with the model waveform, and one of the scanning points at which the highest coincidence exists between both the actual and model waveforms, is determined as a position of the pattern edge.