Scanning electron microscope
US6365898B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1999 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | Sep 13, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2608
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A scanning electron microscope has means for generating a beam of electrons which is scanned over a specimen held within a holder in a chamber which contains a gaseous medium. A negative potential is applied to the holder so as to generate an electric field which accelerates secondary electrons, formed by the interaction or the primary beam with the specimen, in a direction away from the specimen surface and into a collision zone in the chamber. In that zone, the accelerated secondary electrons collide with gas molecules of the gaseous medium, thereby initiating a cascade of collisions which, in effect, amplifies the secondary electron signal. That signal (which may take the form of photons generated as a result of the collisions) is detected by detecting means, such as a photo-multiplier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.