摘要 |
One embodiment relates to a focused electron beam imaging apparatus. The apparatus includes an electron beam column, an electron source, a gun lens, a pre-scanning deflector, a main scanning deflector, an objective lens, and a detector. The pre-scanning deflector comprises a 12-pole electrostatic deflector which is configured to controllably deflect the electron beam away from the optical axis of the electron beam column. Another embodiment relates to a method of scanning an electron beam over a target substrate in a focused electron beam imaging instrument. The electron beam is controllably deflected, without third-order deflection aberrations, away from an optical axis of an electron beam column using a pre-scanning deflector. The electron beam is then controllably deflected back towards the optical axis using a main scanning deflector so that the electron beam passes through a center of an objective electron lens. Other embodiments, aspects and features are also disclosed. |