Patent application number | Description | Published |
20110235395 | SEMICONDUCTOR MEMORY DEVICE AND WRITING METHOD THEREOF - A memory cell array includes memory transistors each including a gate insulating film formed on a semiconductor substrate, a gate electrode formed on the gate insulating film, and a variable resistance film formed on the gate electrode and made of a variable resistance material having variable resistance and is configured by plural memory strings disposed with longer direction extending in a first direction and including plural series-connected memory transistors. Word lines are disposed with a longer direction extending in a second direction orthogonal to the first direction, and connected commonly to the gate electrodes of the plural memory transistors lined up in the second direction. A plate line is disposed to sandwich the variable resistance film with the gate electrode. First voltage terminals supply a certain voltage to first ends of the plural memory strings. Second voltage terminals supply a certain voltage to second ends of the plural memory strings. | 09-29-2011 |
20120217461 | SEMICONDUCTOR MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME - A semiconductor memory device according to an embodiment includes: first lines provided on a substrate; second lines provided between the first lines and the substrate so as to intersect the first lines; and a first memory cell array including first memory cells, each of the first memory cells being provided at respective intersections of the first lines and the second lines and including a current rectifying element and a variable resistor connected in series. The variable resistor of the first memory cell includes a first recording layer and a second recording layer, the first recording layer being made of an oxide of a first metal material, the second recording layer being made of the first metal material and being formed so as to contact with the first recording layer. The second recording layer is closer to the first line than the first recording layer is. | 08-30-2012 |
20120217464 | NONVOLATILE STORAGE DEVICE - A nonvolatile storage device is formed by laminating a plurality of memory cell arrays, the memory cell array including a plurality of word lines, a plurality of bit lines, and memory cells. The memory cell includes a current rectifying device and a variable resistance device, the variable resistance device includes a lower electrode, an upper electrode, and a resistance change layer including a conductive nano material formed between the lower electrode and the upper electrode, one of the variable resistance devices provided adjacent to each other in the laminating direction has titanium oxide (TiOx) between the resistance change layer and the lower electrode serving as a cathode, the other of the variable resistance devices provided adjacent to each other in the laminating direction has titanium oxide (TiOx) between the resistance change layer and the upper electrode serving as a cathode. | 08-30-2012 |
20130182488 | NON-VOLATILE SEMICONDUCTOR MEMORY AND DATA PROCESSING METHOD IN NON-VOLATILE SEMICONDUCTOR MEMORY - A non-volatile semiconductor memory according to an embodiment includes: a data storage unit including a memory cell array and a writing circuit; an encoder that directs the writing circuit to write write data to the memory cell array; a writing determining circuit that determines whether the writing of the write data to the memory cell array within a predetermined number of writing operations fails or succeeds, inverts the write data to generate new write data when the writing of the write data fails, and directs the writing circuit to write the new write data to the memory cell array; a switching circuit that inverts read data which is read from the memory cell to generate new read data when the writing determining circuit determines that the writing of the write data fails; and a decoder that decodes the read data into the information data. | 07-18-2013 |
20130301339 | SEMICONDUCTOR MEMORY DEVICE - A control circuit controls a voltage applied to a memory cell array. A first electrode contacts to a first surface of a variable resistance element, while a second electrode contacts to a second surface of the variable resistance element. The first electrode is configured by a metal, and the second electrode is configured by a P type semiconductor. The control unit, when performing a setting operation of a memory cell, applies a voltage such that a current flows in a direction from the first electrode toward the second electrode. | 11-14-2013 |
20140036571 | SEMICONDUCTOR MEMORY DEVICE AND OPERATION METHOD THEREOF - A semiconductor memory device according to an embodiment includes a control circuit configured to apply a first voltage to a selected first line, apply a second voltage to a selected second line, and apply a third voltage and a fourth voltage to a non-selected first line and a non-selected second line in a setting operation, respectively. The control circuit includes a detection circuit configured to detect a transition of a resistance state of a selected memory cell using a reference voltage. The control circuit is configured to execute a read operation in which the control circuit applies the third voltage to the selected first line and the non-selected first line, applies the second voltage to the selected second line, and applies the fourth voltage to the non-selected second line, and set the reference voltage based on a voltage value of the selected second line. | 02-06-2014 |
20140048761 | SEMICONDUCTOR MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME - A semiconductor memory device according to an embodiment comprises: a semiconductor substrate; and a memory cell block formed on the semiconductor substrate and configured having a plurality of memory cell arrays, each of the memory cell arrays including a plurality of column lines, a plurality of row lines, and a plurality of memory cells disposed at each of intersections of the plurality of column lines and the plurality of row lines, each of the memory cells including a variable resistance element having a transition metal oxide as a material, at least one of the plurality of column lines and the plurality of row lines being a polysilicon wiring line having polysilicon as a material, and the memory cell block including a block film between the variable resistance element of the memory cell and the polysilicon wiring line. | 02-20-2014 |
20140061578 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - A nonvolatile semiconductor memory device below comprises: a memory cell array configured having memory cells arranged therein disposed at intersections of a plurality of first lines and a plurality of second lines formed so as to intersect each other, and the memory cells each comprising a variable resistance element; and a control circuit configured to select and drive the first lines and the second lines. The variable resistance element is configured by a transition metal oxide film. The variable resistance element is electrically connected to a first electrode configured from a metal at a first surface and is electrically connected to a second electrode at a second surface which is on an opposite side to the first surface. A first insulating film is formed between the first electrode and the variable resistance element. The first insulating film is formed by a first material that is formed by covalent binding. | 03-06-2014 |
20140063911 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND METHOD OF FORMING SAME - A nonvolatile semiconductor memory device according to an embodiment comprises: a memory cell array including a plurality of memory layers; and a control unit configured to control a voltage applied to the memory cell array. Each of the memory layers comprises a first line and a second line, and further includes a memory cell disposed between the first line and the second line and including a variable resistance element. The control unit is configured to, when executing a forming operation on the memory cell array, execute the forming operation sequentially on the plurality of memory layers. The forming operation is executed sequentially on the memory layers in ascending order of a magnitude of a non-selected current flowing in a non-selected memory cell during the forming operation. | 03-06-2014 |
20140138597 | NON-VOLATILE SEMICONDUCTOR MEMORY DEVICE - First conductive layers extend in a first direction horizontal to a substrate as a longitudinal direction, and are stacked in a direction perpendicular to a substrate. An interlayer insulating layer is provided between the first conductive layers. The variable resistance layers functioning as a variable resistance element are formed continuously on the side surfaces of the first conductive layers and the interlayer insulating layer. A columnar conductive layer is provided on the side surfaces of the first conductive layers and the interlayer insulating layer via the variable resistance layers. First side surfaces of the first conductive layers are recessed from a second side surface of the interlayer insulating layer in the direction away from the columnar conductive layers. | 05-22-2014 |
20140241037 | SEMICONDUCTOR MEMORY DEVICE - A memory cell array includes first wiring lines, and second wiring lines, the first and second wiring lines intersecting, and memory cells disposed in the intersections of the first and second wiring lines, the memory cells including a variable resistance element. A control circuit controls voltages of selected first and second wiring lines. The first wiring lines are arranged at a first pitch in a first direction perpendicular to a substrate and extend in a second direction parallel to the substrate. The second wiring lines are arranged at a second pitch in the second direction and extend in the first direction. The control circuit is configured to change voltages applied to a selected first wiring line according to the positions of the selected first wiring lines in the first direction. | 08-28-2014 |
20150060749 | NONVOLATILE MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME - According to an embodiment, a first impurity diffusion layer is provided in a region lower than a drain region and the first impurity diffusion layer diffuses impurities of a second conductivity type. A second impurity diffusion layer is provided between the drain region and the first impurity diffusion layer, and the second impurity diffusion layer diffuses impurities of a first conductivity type or the second conductivity type, and a concentration of the second impurity diffusion layer is lower than that of the first conductivity type of the drain region and that of the second conductivity type of the first impurity diffusion layer. | 03-05-2015 |