摘要 |
The invention relates to an assembly for inspecting the surface of a sample. The assembly comprises two or more multi-beam electron column units. Each unit comprises: - a single thermal field emitter for emitting a diverging electron beam towards a beam splitter, - wherein the beam splitter comprises a first multi-aperture plate comprising multiple apertures for creating multiple primary electron beams, - a collimator lens for collimating the diverging electron beam from the emitter, - an objective lens unit for focusing said multiple primary electron beams on said sample, and - a multi-sensor detector system for separately detecting the intensity of secondary electron beams created by each one of said focused primary electron beams on said sample. The two or more multi-beam electron column units are arranged adjacent to each other for inspecting different parts of the surface of the sample at the same time. |