Spatial filtering method for failure analysis of a device

摘要

A spatial filtering method providing quick detection and visualization of irregularities of SEM images of components such as integrated circuits includes the steps of: (a) acquiring a digital image as a two-dimensional array of pixel data from an original image; (b) calculating a first Fourier transform to generate a two-dimensional array of complex data; (c) calculating a power spectrum to provide a real function representing a weighting of each spatial frequency in the original image; (d) generating a mask for suppressing regular structures of the original image and undesirable artifacts introduced by the acquiring of the digital image in step (a); (e) dilating the mask generated in step (d) by extending masking spots generated therein to increase the suppression of regular structures of the original image; (f) applying the mask dilated in step (e) to the data from the first Fourier transform for removing periodic data to result in a second Fourier transform; (g) calculating an inverse Fourier transform of the data of the second Fourier transform to obtain a spatially filtered image; (h) scaling the spatially filtered image to greyscale; and (i) providing a visual representation of the greyscaled image obtained in step (h).