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. 20, 1999
Filed:
Apr. 14, 1997
Keisuke Koga, Kyoto, JP;
Yoshikazu Hori, Hyogo, JP;
Takehito Yoshida, Tokyo, JP;
Yuka Yamada, Kanagawa, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A withdrawn electrode is formed on a silicon substrate with intervention of upper and lower silicon oxide films each having circular openings corresponding to regions in which cathodes are to be formed. Tower-shaped cathodes are formed in the respective openings of the upper and lower silicon oxide films and of the withdrawn electrode. Each of the cathodes has a sharply tapered tip portion having a radius of 2 nm or less, which has been formed by crystal anisotropic etching and thermal oxidation process for silicon. The region of the silicon substrate exposed in the openings of the upper and lower silicon oxide films and the cathode have their surfaces coated with a thin surface coating film made of a material having a low work function.