Assessment system, method of assessing

Abstract

Assessment systems and methods are disclosed. In one arrangement, charged particles are directed in sub-beams arranged in a multi-beam towards a sample. A plurality of control electrodes define a control lens array. Each control lens in the control lens array is aligned with a sub-beam path of a respective sub-beam of the multi-beam and configured to operate on the respective sub-beam. A plurality of objective electrodes define an objective lens array that directs the sub-beams onto a sample. Objective lenses are aligned with a sub-beam path aligned with a respective control lens. Selectable landing energies are implemented for a sub-beam of the multi-beam by applying corresponding potentials to the control electrodes and the objective electrodes. A controller is configured to select corresponding potentials so a spatial relationship between an image plane of the system and all control electrodes and objective electrodes is the same for each selectable landing energy.