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:
Aug. 26, 2014
Filed:
Aug. 05, 2013
Sharp Kabushiki Kaisha, Osaka, JP;
Elpida Memory, Inc., Tokyo, JP;
Kazuya Ishihara, Osaka, JP;
Yukio Tamai, Osaka, JP;
Takashi Nakano, Osaka, JP;
Akiyoshi Seko, Tokyo, JP;
Sharp Kabushiki Kaisha, Osaka-shi, Osaka, JP;
Elpida Memory, Inc., Chou-ku, Tokyo, JP;
Abstract
A semiconductor memory device includes a memory cell array having a plurality of memory cells arranged in a matrix, each memory cell being configured such that a variable resistance element and a selection transistor are connected in series. A set operation for a memory cell (an operation of converting the resistance of the variable resistance element to a low resistance) is performed by applying a set voltage pulse for a longer time than that for a reset operation (an operation of converting the resistance of the variable resistance element to a high resistance) while limiting, using the selection transistor, an electric current flowing in the set operation to a certain low electric current, and by simultaneously applying the set voltage pulse to the plurality of memory cells.