Semiconductor device having a cold cathode
US4766340A · kind A · utility
Inventors
Key dates
| Filing date | Mar 2, 1987 |
| Grant date | Aug 23, 1988 |
| Priority date | — |
| Expiry date | Mar 2, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J1/308
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a semiconductor cathode, the electron-emitting part of a pn junction is provided in the tip of a projecting portion of the semiconductor surface which is situated within an opening in an insulating layer on which an acceleration electrode is disposed. Due to the increased electric field near the tip, a reduction of the work function (Schottky effect) is obtained. As a result, cathodes can be realized in which a material reducing the work function, such as caesium, may be either dispensed with or replaced, if required, by another material, which causes lower work function, but is less volatile. The field strength remains so low that no field emission occurs and serarate cathodes can be driven individually, which is favorable for applications in electron microscopy and electron lithography.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.