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. 26, 2009
Filed:
Jul. 20, 2007
Yukio Tamai, Tsuchiura, JP;
Akihito Sawa, Tsukuba, JP;
Yukio Tamai, Tsuchiura, JP;
Akihito Sawa, Tsukuba, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Institute of Advanced Industrial Science and Technology, Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device comprises a memory cell including a variable resistance element changing its electric resistance by voltage application and having current-voltage characteristics in which a positive bias current flowing when a positive voltage is applied from one electrode as a reference electrode to the other electrode through an incorporated rectifier junction is larger than a negative bias current, a memory cell selection circuit for selecting the memory cell from the memory cell array, a voltage supply circuit for supplying a voltage to the memory cell so that a predetermined positive voltage corresponding to the reading operation is applied to the other electrode of the variable resistance element, in the reading operation, and a readout circuit for detecting the amount of the positive bias current and reading the information stored in the selected memory cell, in order to suppress the reading disturbance of the memory cell.