Abstract
A novel principle of an in-lens detector of very slow electrons is described and the detector efficiency discussed. The detector was built into a coaxial column for a Cylindrical Mirror Analyser for Auger electron microanalysis. In order to obtain a very low energy scanned imaging, a cathode lens was formed between the final electrode of the column and a negatively biased specimen. The signal electrons accelerated within the cathode lens field enter the column and after being mirrored back impact a micro-channel-plate based detector fitted around the optical axis. The acceptance of the detector, expressed as a ratio of the number of electrons impacting the detector to the full emission of a cosine source, was calculated to be 0.86 for 1 eV and 0.985 for 10 eV electrons. Then, the efficiency of conversion into output pulses is 0.35 and 0.31, respectively; these parameters are superior to those of conventional SEM detectors for secondary electrons. Micrographs taken at low energies ranging down to units of eV are presented. (C) 2000 Elsevier Science B.V. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 99-110 |
| Number of pages | 12 |
| Journal | Ultramicroscopy |
| Volume | 81 |
| Issue number | 2 |
| Publication status | Published - Mar 2000 |
Keywords
- LOW-ENERGY
- OPTICAL-PROPERTIES
- CATHODE LENS
- MICROSCOPY
- RESOLUTION