Electron gun and charged particle beam device having an aperture with flare-suppressing coating
US9293293B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2012 |
| Grant date | Mar 22, 2016 |
| Priority date | — |
| Expiry date | May 22, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/06316
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The objective of the present application is to suppress the occurrence of flares and to reduce the amount of secondary electrons arising at an aperture provided to the lead-out electrode of an electron gun. By coating a thin film having a low rate of secondary electron emission such as carbon onto the aperture of a lead-out electrode closest to an electron source in an electron gun, it is possible to reduce the amount of secondary electrons arising. Secondary electrons arising at the lead-out electrode, are reduced, and so as a result, flare is reduced. By incorporating two apertures to the lead-out electrode, and applying to the two apertures a potential that is equipotential to the lead-out electrode, it is possible to eliminate an electric field from seeping from under to over the lead-out electrode. Secondary electrons arising when an electron beam impacts the lead-out electrode cease to incur force in the direction of passage from the lead-out electrode, and consequently there is a reduction in flares.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.