Method of preparation of electron emissive materials
US3972770A · kind A · utility
8Cited by
5References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1975 |
| Grant date | Aug 3, 1976 |
| Priority date | — |
| Expiry date | Mar 21, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2201/3423
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Preferential etches for Gallium Arsenide and Gallium Aluminum Arsenide materials provide a novel single crystalline layer thin film of GaAs for use as a free standing transmission secondary electron emitter or as a photocathode layer on an intermediate epitaxial layer of GaAlAs. Etching of a central area of a substrate layer of GaAs provides an annular rim supporting structure for the epitaxial GaAlAs and GaAs layers. A particular composition of hydrogen peroxide and ammonium hydroxide preferentially etches GaAs while hydrochloric acid preferentially etches GaAlAs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.