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:
Sep. 27, 1994
Filed:
Jun. 26, 1991
Naohiro Matsukawa, Kamakura, JP;
Junichi Miyamoto, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A memory cell transistor includes a semiconductor substrate, a N-type source region, a N-type drain region, a control gate and a P.sup.+ -type emitter region, which is formed in the surface region of the drain region. An insulating film overlies the source region, the drain region, the emitter region, and the control gate. A contact hole is formed in the insulating film so that the surface of the emitter region is exposed. An emitter electrode is formed in and around the contact hole. A PNP vertical bipolar transistor is constituted by the semiconductor substrate serving as a collector region, a P.sup.+ -type buried layer serving as a collector contact, and the drain region serving as a base region.