Publication detail

Collection Efficiency of the Detector of Secondary Electrons in SEM.

KONVALINA, I. MÜLLEROVÁ, I.

Czech title

Sběrová účinnost detektoru sekundárních elektronů v REM.

English title

Collection Efficiency of the Detector of Secondary Electrons in SEM.

Type

conference paper

Language

en

Original abstract

In order to collect the secondary electrons (SE), scanning electron microscopes (SEM) are equipped with the Everhart-Thornley (ET) type detector. The electrostatic field of the front grid, biased to a positive potential of several hundred volts , is to attract all SE of kinetic energy below 50 eV or at least those from the SE spectrum peak at 1¸3 eV. However, the detection quantum efficiency (DQE) of such detectors has been found to be significantly lower than one, which is mainly given by their low collection efficiency. The electrostatic field of the grid cannot sufficiently penetrate toward the specimen and influence the trajectories of SE owing to grounded electrodes surrounding the specimen (specimen alone and its holder, specimen stage, pole piece of the objective lens, etc).

Czech abstract

Za účelem sběru sekundárních elektronů (SE) jsou rastrovací elektronové mikroskopy (REM) vybaveny Everhart-Thornley-ho detektorem. Elektrostatické pole síťky na kladném potenciálu několika set voltů má přitahovat všechny SE s kinetickou energií pod 50 eV nebo alespoň ty s energií v blízkosti píku 1-3 eV ve spektru SE. Detekční kvantová účinnost (DQE) mnoha detektorů je ale výrazně menší než jedna a to je převážně dáno jejich malou sběrovou účinností. Elektrostatické pole síťky nemůže dostatečně pronikat ke vzorku a ovlivňovat trajektorie SE kvůli elektrodám na zemním potenciálu v okolí vzorku (samotný vzorek, jeho držák, stolek, pólové nástavce objektivu, atd.).

English abstract

In order to collect the secondary electrons (SE), scanning electron microscopes (SEM) are equipped with the Everhart-Thornley (ET) type detector. The electrostatic field of the front grid, biased to a positive potential of several hundred volts , is to attract all SE of kinetic energy below 50 eV or at least those from the SE spectrum peak at 1¸3 eV. However, the detection quantum efficiency (DQE) of such detectors has been found to be significantly lower than one, which is mainly given by their low collection efficiency. The electrostatic field of the grid cannot sufficiently penetrate toward the specimen and influence the trajectories of SE owing to grounded electrodes surrounding the specimen (specimen alone and its holder, specimen stage, pole piece of the objective lens, etc).

Keywords in Czech

sběrová účinnost, ET detektor, sekundární elektrony

Keywords in English

collection efficiency, ET detector, secondary electrons

Released

12.07.2004

Location

Brno

ISBN

80-239-3246-2

Book

Recent Trends in Charged Particle Optics and Surface Physics Instrumentation

Pages count

2

BIBTEX


@inproceedings{BUT21740,
  author="Ivo {Konvalina} and Ilona {Müllerová},
  title="Collection Efficiency of the Detector of Secondary Electrons in SEM.",
  booktitle="Recent Trends in Charged Particle Optics and Surface Physics Instrumentation",
  year="2004",
  month="July",
  address="Brno",
  isbn="80-239-3246-2"
}