Deflection system of scanning electron microscope for inspecting e.g. lithography mask has controller for changing illuminated field position, displacing imaged region on detector in common with illuminated field

摘要

The system has an illumination device (31) directing energy to the object (3), which produces charged particles, a deflector (23,24) producing a variable deflection field, a position resolving detector (5) and a controller (25) for controlling the illumination device to change the illuminated field position and controlling the first deflector to displace the imaged region (7) on the detector in common with the illuminated field in the object plane. Independent claims are also included for the following: a particle beam deflector and a method of operating a deflector.