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:
Dec. 07, 1993
Filed:
Mar. 23, 1993
Kenji Hosogi, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A microminiature vacuum tube and a process for fabrication thereof. The tube is formed on a compound semiconductor substrate using solid state semiconductor fabrication techniques. A straight line path for electron flow is provided by forming an emitter and collector in the same plane. The emitter and collector are formed in a low resistance layer of a compound semiconductor substrate, such as by etching a recess through the low resistance layer and into the substrate to define a separate emitter and collector. Preferential etching techniques are utilized to form a sharp-edge in at least the emitter portion of the recess. A gate is formed in the recess proximate to but out of the plane for electron flow. The use of microminiature solid state fabrication technique allows the recess to be formed at submicron size to reduce the voltage requirements on the microminiature vacuum tube.