Patent ID: 8089044

Claim:
A method for correcting astigmatism of an electronic optical column of an electron emission spectromicroscope, comprising at least the steps of: forming a reference structure on a surface of a sample comprising a structure of interest to be imaged, the dimensions of the exterior contour of the reference structure, along two axes perpendicular to each other and lying in a plane parallel to the surface of the sample, being substantially similar, imaging the reference structure by the spectromicroscope with secondary electrons and with care level photoelectrons, eliminating astigmatism defects appearing during the imaging of the reference structure with secondary electrons and with core level photoelectrons, a material of the reference structure being chosen such that, during core level photoelectron imaging, the contrast C between the average intensity I a of the material of the reference structure and the average intensity I b of the material of the sample is such that: C = I a - I b I a + I b ≥ 0.2 .