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:
May. 21, 2002
Filed:
Mar. 05, 1999
Lee H. Veneklasen, Castro Valley, CA (US);
William J. DeVore, Hayward, CA (US);
Rudy F. Garcia, Neward, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
An enhanced electron source in most respects similar to a standard cathode assembly for an electron gun includes an electron emitter surrounded by a suppressor electrode, the emitted electrons passing through an extractor electrode. Additionally, the suppressor electrode includes a small ring shaped permanent magnet surrounding the opening in the suppressor electrode through which the emitter tip protrudes. The resulting magnetic field is aligned with the beam axis, and includes a tail which forms a very short focal length magnetic lens immediately following the emitter tip. This magnetic field collimates the electron beam before it enters the downstream electrostatic gun lens, thus increasing the effective angular intensity of the cathode assembly. The aberrations of this collimating lens are very low so that its useful brightness is not reduced. Also the influence of guns lens aberrations is reduced because a smaller aperture angle in the gun lens may be used to obtain higher beam current.