Method of determination of a threshold which is applicable to determining the critical dimension of at least one category of images by electron microscopy at a scanning atomic force

摘要

The present invention relates to a method for determining a threshold which is applicable to determine the critical dimension (cd) of a category of patterns (m) imaged by electron scanning atomic force, said process comprising the following steps: - from a plurality of units (m), acquisition (101) of a pair of images (im1, im2) for each pattern (m): a first image (im1) being obtained by means of an instrumentation imaging using the technique of atomic force microscopy and scanning electron microscopy, called the instrumentation cd - sem, which it is sought to determine said threshold; a second image (im2) being obtained by means of an instrumentation of reference, using a different technique of the cd technique - sem; for each pair of images (im1, im2): (102) of a critical dimension (cd) via the reference image (im2) obtained by means of the instrumentation of reference, and determination (103) of an empirical threshold (s) can be applied to the image (im1) obtained by means of the instrumentation cd - sem so that said threshold empirical (s) corresponds substantially to the critical dimension of reference (cd); - determination (104) of the threshold (s) can be applied to a group of motifs (m), said threshold (s) being determined from a plurality of thresholds (semp empirical).