Abstract: A method of determining a brightness (Br) of a charged particle beam (11) focused by a focusing lens (120) toward a sample (10) in a charged particle beam imaging device (100) is described. The method includes (a) taking one or more images (hf, 1 . . . N) of the sample with the charged particle beam imaging device; (b) retrieving one or more beam profiles (gf, 1 . . . N) of the charged particle beam from the one or more images; and (c) determining the brightness (Br) of the charged particle beam (11) based on at least the one or more beam profiles (gf, g1 . . . N), a probe current (Ip) of the charged particle beam, and a landing potential (LE) of the charged particle beam. Optionally, the brightness (Br) determined as above can be used for determining a size (Dvirt) of a source (105) of the charged particle beam (11). Further, a charged particle beam imaging device (100) configured for any of the methods described herein is provided.

Abstract: A method of determining aberrations of a charged particle beam (11) focused by a focusing lens (120) toward a sample (10) in a charged particle beam system is described. The method includes: (a) taking one or more images of the sample at one or more defocus settings to provide one or more taken images (h1...N); (b) simulating one or more images of the sample taken at the one or more defocus settings based on a set of beam aberration coefficients (iC) and a focus image of the sample to provide one or more simulated images; (c) comparing the one or more taken images and the one or more simulated images for determining a magnitude (Ri) of a difference therebetween; and (d) varying the set of beam aberration coefficients (iC) to provide an updated set of beam aberration coefficients (i+1C) and repeating (b) and (c) using the updated set of beam aberration coefficients (i+1C) in an iterative process for minimizing said magnitude (Ri).

Abstract: A method of determining aberrations of a charged particle beam (11) focused by a focusing lens (120) with a given numerical aperture (NA) toward a sample (10) in a charged particle beam system is described. The method includes: (a.) simulating, based at least on the given numerical aperture (NA), one or more beam cross sections at one or more first defocus settings for each of two or more different values of a first beam aberration coefficient (C1) of a set of beam aberration coefficients (C1 . . . n), to provide a plurality of first simulated beam cross sections; (b.) extracting two or more values of a first aberration characteristic (˜C1) that is related to the first beam aberration coefficient (C1) from the plurality of first simulated beam cross sections; (c.) determining a first dependency between the first beam aberration coefficient (C1) and the first aberration characteristic (˜C1); (d.

Abstract: A method of determining a beam convergence of a charged particle beam (11) focused by a focusing lens (120) toward a sample (10) in a charged particle beam system (100) is provided. The method includes (a) taking one or more images of the sample when the sample is arranged at one or more defocus distances from a respective beam focus of the charged particle beam; (b) retrieving one or more beam cross sections from the one or more images; (c) determining one or more beam widths from the one or more beam cross sections; and (d) calculating at least one beam convergence value based on the one or more beam widths and the one or more defocus distances. Further, a charged particle beam system for imaging and/or inspecting a sample that is configured for any of the methods described herein is provided.

Abstract: A method of determining a beam convergence of a charged particle beam (11) focused by a focusing lens (120) toward a sample (10) in a charged particle beam system (100) is provided. The method includes (a) taking one or more images of the sample when the sample is arranged at one or more defocus distances from a respective beam focus of the charged particle beam; (b) retrieving one or more beam cross sections from the one or more images; (c) determining one or more beam widths from the one or more beam cross sections; and (d) calculating at least one beam convergence value based on the one or more beam widths and the one or more defocus distances. Further, a charged particle beam system for imaging and/or inspecting a sample that is configured for any of the methods described herein is provided.

Abstract: A method of determining aberrations of a charged particle beam (11) focused by a focusing lens (120) toward a sample (10) in a charged particle beam system is described. The method includes: (a) taking one or more images of the sample at one or more defocus settings to provide one or more taken images (h1...N); (b) simulating one or more images of the sample taken at the one or more defocus settings based on a set of beam aberration coefficients (iC) and a focus image of the sample to provide one or more simulated images; (c) comparing the one or more taken images and the one or more simulated images for determining a magnitude (Ri) of a difference therebetween; and (d) varying the set of beam aberration coefficients (iC) to provide an updated set of beam aberration coefficients (i+1C) and repeating (b) and (c) using the updated set of beam aberration coefficients (i+1C) in an iterative process for minimizing said magnitude (Ri).