Invention Grant
- Patent Title: Nonvolatile semiconductor memory device
- Patent Title (中): 非易失性半导体存储器件
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Application No.: US13424788Application Date: 2012-03-20
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Publication No.: US08811089B2Publication Date: 2014-08-19
- Inventor: Koki Ueno
- Applicant: Koki Ueno
- Applicant Address: JP Tokyo
- Assignee: Kabushiki Kaisha Toshiba
- Current Assignee: Kabushiki Kaisha Toshiba
- Current Assignee Address: JP Tokyo
- Agency: Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2011-211037 20110927
- Main IPC: G11C11/34
- IPC: G11C11/34 ; G11C16/34 ; G11C11/56 ; G11C16/08 ; G11C16/04 ; G11C16/10 ; G11C16/28 ; G11C16/16

Abstract:
A nonvolatile semiconductor memory device according to the embodiment comprises a memory cell array including plural memory cells operative to store data nonvolatilely in accordance with plural different threshold voltages; and a control unit operative to, in data write to the memory cell, execute write loops having a program operation for changing the threshold voltage of the memory cell and a verify operation for detecting the threshold voltage of the memory cell after the program operation, the control unit, in data write for changing one threshold voltage of the plural threshold voltages, executing the verify operation, when the number of write loops to the memory cell becomes more than a certain defined number, using a condition that can pass the verify operation easier than that when the number of write loops is equal to or less than the certain defined number.
Public/Granted literature
- US20130077408A1 NONVOLATILE SEMICONDUCTOR MEMORY DEVICE Public/Granted day:2013-03-28
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