Thermal-field type electron source composed of transition metal carbide material
US9490098B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 2016 |
| Grant date | Nov 8, 2016 |
| Priority date | — |
| Expiry date | Jan 11, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/06316
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron source is made from mixed-metal carbide materials of high refractory nature. Producing field-enhanced thermionic emission, i.e., thermal-field or extended Schottky emission, from these materials entails the use of a certain low work function crystallographic direction, such as, for example, (100), (210), and (310). These materials do not naturally facet because of their refractory nature. The disclosed electron source made from transition metal carbide material is especially useful when installed in a scanning electron microscope (SEM) performing advanced imaging applications that require a high brightness, high beam current source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.