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. 25, 1993
Filed:
Feb. 06, 1992
Hiroshi Komatsu, Suwa, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
According to an embodiment of the present invention, a planar microelectronic vacuum triode comprises a cathode with three tips for electron emission that have been sharpened to points better than 1000 .ANG. by a microfabrication process of over-etching (excess etching) the cathode electrode layer. The cathode tips and, alternatively, an anode electrode too are elevated above the surface of a substrate such that a straight-line path exists for electrons to flow from the cathode tips to the anode. A self-aligned fabrication process is used to advantage to have the edge of a gate electrode that is nearest to the cathode and its tips complement the adjacent edge of the cathode electrode. The combination results in very low threshold voltages needed to initiate the electron flow and a high yield of anode current compared to cathode current. The addition of a shield electrode to the triode produces a tetrode device that exhibits a very high anode resistance.