Charged particle system, aperture array, charged particle tool and method of operating a charged particle system

A charged particle tool, comprising:

• a charged particle system configured to generate a charged particle multi-beam along a charged particle multi-beam path;
• a charged particle projection system configured to direct the charged particle multi-beam along the charged particle multi-beam path onto a sample;
• and
• an aperture array having a geometric center aligned with a primary axis of the charged particle system, the aperture array comprising:
• a pattern of apertures, wherein the pattern of apertures comprises a superposition of:
• a template pattern at a first rotation about the geometric center and a first magnification, and
• the template pattern at a second rotation about the geometric center and a second magnification.

A non-transitory computer readable medium that stores a set of instructions that is executable by at least one processor of a computing device to cause the computing device to perform operations for operating a charged particle system, the charged particle system comprising an aperture array in which is defined an array of apertures, a beam-limit array arranged downbeam of the aperture array and in which is defined an array of beam-limit apertures, and a condenser lens system arranged between the aperture array and the beam-limit array, the operations comprising:

• sending a first signal that causes the charged particle system to pass a charged particle beam through the apertures of the aperture array;
• sending a second signal that causes the charged particle system to operate the condenser lens system at one or more different rotation settings, each rotation setting defining a different beam path between the aperture array and the beam-limit array;
• and
• sending a third signal that causes the charged particle system to, for each rotation setting, direct the charged particles from the aperture array through each of the beam-limit apertures of the beam-limit array.