The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 06, 2004
Filed:
Jul. 29, 1999
Andres Fernandez, Dublin, CA (US);
Timothy Thomas, Portland, OR (US);
Xiaolan Chen, Beaverton, OR (US);
Steven T. Coyle, Newark, CA (US);
Ming Yu, Fremont, CA (US);
Marian Mankos, San Francisco, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
A photocathode as a source of electron beams, having a substrate of optically transmissive diamond and a photoemitter. A photocathode with a single emitting region provides a single electron beam; a photocathode with multiple emitting regions provides multiple electron beams. The photoemitter is positioned on the side of the diamond substrate opposite the surface on which the illumination is incident, and has an irradiation region at the contact with the optically transmissive diamond, and an emission region opposite the irradiation region, these regions being defined by the path of the illumination. The diamond substrate at the irradiation region/emission region interface conducts heat away from this focused region of illumination on the photocathode. Alternately, a diamond film is used for heat conduction, while another material is used as a substrate to provide structural support. The thermal conductivity of diamond is at least three orders of magnitude greater than that of fused silica, which is an alternative substrate material for photocathodes. This allows for efficient conduction of heat away from the irradiation region/emission region interface, and therefore allows higher currents to be achieved from the photocathode. This, in turn, permits higher throughput rates in applications including electron beam lithography.