Trajektorie sekundárních elektronů v rastrovacím elektronovém mikroskopu

The Trajectories of Secondary Electrons in the Scanning Electron Microscope.

journal article - other

en

Three-dimensional simulations of the trajectories of secondary electrons (SE) in the scanning electron microscope have been performed for plenty of real configurations of the specimen chamber, including all its basic components. The primary purpose was to evaluate the collection efficiency of the Everhart-Thornley detector of SE and to reveal fundamental rules for tailoring the set-ups in which efficient signal acquisition can be expected. Intuitive realizations about the easiness of attracting the SEs towards the biased front grid of the detector have shown themselves as likely false, and all grounded objects in the chamber have been proven to influence the spatial distribution of the signal-extracting field. The role of the magnetic field penetrating from inside the objective lens is shown to play an ambiguous role regarding possible support for the signal collection.

Pro mnoho reálných konfigurací komory vzorku byly provedeny 3D simulace trajektorií sekundárních elektronů (SE) v rastrovacím elektronovém mikroskopu, včetně všech základních komponent. Hlavním cílem bylo vyčíslit sběrovou účinnost Everharta-Thornleyho detektoru sekundárních elektronů a nalézt základní pravidla pro upravování uspořádání aby se dosáhlo lepší signálové akvizice. Původní myšlenka snadného přitažení SE k mřížce detektoru se ukázala mylná, protože uzemněné objekty v komoře prokazatelně ovlivňují prostorové rozložení extrakčních polí. Magnetické pole penetrující z objektivu má dvouznačnou roli týkající se možné podpory sběru signálu.

Three-dimensional simulations of the trajectories of secondary electrons (SE) in the scanning electron microscope have been performed for plenty of real configurations of the specimen chamber, including all its basic components. The primary purpose was to evaluate the collection efficiency of the Everhart-Thornley detector of SE and to reveal fundamental rules for tailoring the set-ups in which efficient signal acquisition can be expected. Intuitive realizations about the easiness of attracting the SEs towards the biased front grid of the detector have shown themselves as likely false, and all grounded objects in the chamber have been proven to influence the spatial distribution of the signal-extracting field. The role of the magnetic field penetrating from inside the objective lens is shown to play an ambiguous role regarding possible support for the signal collection.

ET detektor, sekundární elektrony, sběrová účinnost

ET detector, secondary electrons, collection efficiency

11.01.2006

0161-0457

SCANNING

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