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Makoto Iwai, Yokohama-Shi JP

Makoto Iwai, Yokohama-Shi JP

Patent application numberDescriptionPublished
20090154241NONVOLATILE SEMICONDUCTOR MEMORY, METHOD FOR READING OUT THEREOF, AND MEMORY CARD - A nonvolatile semiconductor memory includes: a memory cell unit including a plurality of memory cells having an electric charge accumulation layer and a control electrode, said memory cells being electrically connected in series; a plurality of word lines, each of which is electrically connected to said control electrode of said plurality of memory cells; a source line electrically connected to said memory cells at one end of said memory cell unit; a bit line electrically connected to said memory cells at the other end of said memory cell unit; and a control signal generation circuit, which during a data readout operation staggers a timing for selecting the word line connected to said memory cells of said memory cell unit from a timing for selecting a non-selected word line connected to a non-selected memory.06-18-2009
20090185423SEMICONDUCTOR MEMORY DEVICE - A semiconductor memory device includes a memory cell array including a plurality of blocks each including a memory cell unit, and a selection transistor which selects the memory cell unit, and a row decoder including a first block selector and a second block selector each of which includes a plurality of transfer transistors which are formed to correspond to the plurality of blocks and arranged adjacent to each other in a word-line direction wherein the diffusion layers are formed to oppose each other in the first block selector and the second block selector, and a width between the diffusion layers of the first block selector and the second block selector adjacent to each other in the word-line direction is made larger than a width between the diffusion layers in each of the first block selector and the second block selector adjacent to each other in the word-line direction.07-23-2009
20100128526MULTI-LEVEL NONVOLATILE SEMICONDUCTOR MEMORY - A memory includes first and second select gate transistors, memory cells which are connected in series between the first and second select gate transistors, a selected word line which is connected to a selected memory cell as a target of a reading, a non-selected word line which is connected to a non-selected memory cell except the selected memory cell, a potential generating circuit for generating a selected read potential which is supplied to the selected word line, and generating a non-selected read potential larger than the selected read potential, which is supplied to the non-selected word line, and a control circuit which changes a set up term of the selected word line and the non-selected word line based on a value of the selected read potential, wherein the value of the selected read potential is selected from two or more potentials.05-27-2010
20100135078NONVOLATILE SEMICONDUCTOR MEMORY - A memory includes first and second select gate transistors, memory cells, a source line, a bit line, a selected word line which is connected to a selected memory cell as a target of a verify reading, a non-selected word line which is connected to a non-selected memory cell except the selected memory cell, a potential generating circuit for generating a selected read potential which is supplied to the selected word line, and generating a non-selected read potential larger than the selected read potential, which is supplied to the non-selected word line, and a control circuit which classifies a threshold voltage of the selected memory cell to one of three groups by verifying which area among three area which are isolated by two values does a cell current of the selected memory cell belong, when the selected read potential is a first value.06-03-2010
20100177563NONVOLATILE SEMICONDUCTOR MEMORY, METHOD FOR READING OUT THEREOF, AND MEMORY CARD - A nonvolatile semiconductor memory includes: a memory cell unit including a plurality of memory cells having an electric charge accumulation layer and a control electrode, said memory cells being electrically connected in series; a plurality of word lines, each of which is electrically connected to said control electrode of said plurality of memory cells; a source line electrically connected to said memory cells at one end of said memory cell unit; a bit line electrically connected to said memory cells at the other end of said memory cell unit; and a control signal generation circuit, which during a data readout operation staggers a timing for selecting the word line connected to said memory cells of said memory cell unit from a timing for selecting a non-selected word line connected to a non-selected memory.07-15-2010
20100232233NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - A nonvolatile semiconductor memory device in which a negative-threshold cell read operation is performed by biasing a source line and well line to a positive voltage includes a first drive circuit that sets at least unselected word line in a floating state at a negative-threshold cell read time.09-16-2010
20110063911SEMICONDUCTOR MEMORY DEVICE - A semiconductor memory device includes a memory cell array including a plurality of blocks each including a memory cell unit, and a selection transistor which selects the memory cell unit, and a row decoder including a first block selector and a second block selector each of which includes a plurality of transfer transistors which are formed to correspond to the plurality of blocks and arranged adjacent to each other in a word-line direction wherein the diffusion layers are formed to oppose each other in the first block selector and the second block selector, and a width between the diffusion layers of the first block selector and the second block selector adjacent to each other in the word-line direction is made larger than a width between the diffusion layers in each of the first block selector and the second block selector adjacent to each other in the word-line direction.03-17-2011
20110286268NONVOLATILE SEMICONDUCTOR MEMORY - A memory includes first and second select gate transistors, memory cells, a source line, a bit line, a selected word line which is connected to a selected memory cell as a target of a verify reading, a non-selected word line which is connected to a non-selected memory cell except the selected memory cell, a potential generating circuit for generating a selected read potential which is supplied to the selected word line, and generating a non-selected read potential larger than the selected read potential, which is supplied to the non-selected word line, and a control circuit which classifies a threshold voltage of the selected memory cell to one of three groups by verifying which area among three area which are isolated by two values does a cell current of the selected memory cell belong, when the selected read potential is a first value.11-24-2011

Patent applications by Makoto Iwai, Yokohama-Shi JP