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. 04, 2007
Filed:
Mar. 16, 2005
Fujio Masuoka, Sendai, JP;
Shinji Horii, Fukuyama, JP;
Takuji Tanigami, Kashihara, JP;
Takashi Yokoyama, Fukuyama, JP;
Fujio Masuoka, Sendai, JP;
Shinji Horii, Fukuyama, JP;
Takuji Tanigami, Kashihara, JP;
Takashi Yokoyama, Fukuyama, JP;
Fujio Masuoka, Sendai-shi, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
The present invention provides a semiconductor memory device including: a semiconductor substrate of a first conductivity type; and a memory cell including: (i) a columnar semiconductor portion formed on the substrate, (ii) at least two charge-storage layers formed around a periphery of the columnar semiconductor portion and divided in a direction vertical to the semiconductor substrate, and (iii) a control gate that covers at least a portion of charge-storage layers, wherein the memory cell is capable of holding two-bit or more data.