| CPC H01J 37/28 (2013.01) [G01B 11/02 (2013.01); H01J 37/222 (2013.01); H01L 22/12 (2013.01); G01B 2210/56 (2013.01); H01J 2237/223 (2013.01); H01J 2237/226 (2013.01); H01J 2237/2817 (2013.01)] | 20 Claims |

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1. A scanning electron microscope (SEM) image-based pitch walk inspection method, comprising:
obtaining an SEM image for a line and space (L/S) pattern formed by multi-patterning technology (MPT), wherein the L/S pattern includes a plurality of lines and spaces that are alternately arranged;
detecting a main pitch of the L/S pattern in the SEM image;
dividing a graph of the main pitch into graphs of component pitches, based on the MPT;
performing a Fast Fourier Transform (FFT) on each graph of the component pitches;
multiplying a phase graph and an intensity graph of the FFT of each graph of the component pitches with each other and obtaining compensated FFT phase graphs that respectively correspond to the graphs of the component pitches;
calculating a pitch walk of the L/S pattern by obtaining differences between phase peak values of the compensated FFT phase graphs; and
determining whether the pitch walk is within an allowable range so as to determine whether to change a condition of a MPT process or to perform a subsequent semiconductor manufacturing process.
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