Patterned heat conducting photocathode for electron beam source
US6376984B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1999 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Jul 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31779
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A photocathode emitter as a source of electron beams, having an optically transmissive substrate patterned to define a protrusion, heat conducting material occupying the space surrounding the protrusion, and a photoemitter layer over the protrusion. The photoemitter is positioned on the side of the substrate opposite the surface on which the illumination is incident, and has an irradiation region at the contact with the top of the protrusion patterned on the substrate, and an emission region opposite the irradiation region, these regions being defined by the path of the illumination. The heat conducting material around the protrusion conducts heat away from this focused region of illumination on the photocathode to allow higher currents to be achieved from the photocathode and thus permits higher throughput rates in applications including electron beam lithography. In one version, the photocathode is fabricated using microfabrication techniques, to achieve a small emission spot size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.