| Patent application number | Description | Published |
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| 20110069532 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array includes a plurality of first wirings, a plurality of second wirings intersecting the plurality of first wirings, and a plurality of memory cells provided at the intersections of the plurality of first and second wirings and each including a non-ohmic element and a variable resistance element connected in series. The control circuit selects one of the plurality of memory cells, generates an erasing pulse for erasing data from the selected memory cell, and supplies the erasing pulse to the selected memory cell. The control circuit executes data erase by applying a voltage of the erasing pulse to the non-ohmic element in the reverse bias direction. | 03-24-2011 |
| 20110103128 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - Nonvolatile semiconductor memory device of an embodiment includes: a memory cell array including a plurality of first and second lines intersecting each other and plural memory cells provided at intersections of the first and second lines and having data written and erased upon application of voltages of the same polarity; and a writing circuit configured to select first and second lines and supply a set or reset pulse to the memory cell through the selected first and second lines. In an erase operation, the writing circuit repeatedly supplies the reset pulse to a selected memory cell until data is erased, by increasing or decreasing voltage level and voltage application time of the reset pulse within a reset region. The reset region, or an aggregate of combinations of voltage level and voltage application time of the reset pulse, is a region where voltage level and voltage application time are negatively correlated. | 05-05-2011 |
| 20110122676 | SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a semiconductor memory device includes: word lines; bit lines; an insulating film; an interlayer insulating film; and a resistance varying material. The word lines, the bit lines and the insulating film configure a field-effect transistor at each of the intersections of the word lines and the bit lines. The field-effect transistor has one of the word lines as a control electrode and one of the bit lines as a channel region. The field-effect transistor and the resistance varying material configure a memory cell having the field-effect transistor and the resistance varying material connected in parallel. Each of the bit lines includes a first surface opposing the word lines, and a second surface on an opposite side to the first surface. The resistance varying material is disposed in contact with the second surface and has a portion thereof in contact with the interlayer insulating film. | 05-26-2011 |
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| 20100202186 | SEMICONDUCTOR MEMORY DEVICE, METHOD OF MANUFACTURING THE SAME, AND METHOD OF SCREENING THE SAME - A semiconductor memory device includes first and second memory cells each including a variable resistance element and a diode and having a pillar shape, and an insulating layer provided between the first memory cell and the second memory cell and including a void. A central portion of the diode has a smaller width than widths of upper and lower portions of the diode. | 08-12-2010 |
| 20100213550 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - The memory cell is located at respective intersections between the first wirings and the second wirings. Each of the memory cells has a rectifier element and a variable resistance element connected in series. The rectifier element includes a p type first semiconductor region, and a n type second semiconductor region. The first semiconductor region is formed of, at least in part, silicon-germanium mixture (Si | 08-26-2010 |
| 20100237314 | RESISTANCE CHANGE TYPE MEMORY - A resistance change type memory of an aspect of the present invention including a first wiring configured to extend in a first direction, a second wiring configured to extend in a second direction crossing the first direction, a series circuit configured to connect to the first and second wirings, the series circuit including a non-ohmic element being more conductive in the first to second wiring direction than in the second to first direction and a resistance change type storage element in which data is stored according to a change of a resistance state, an energy supplying circuit configured to connect to the first wiring to supply energy to the first wiring, the energy being used to store the data in the resistance change type storage element, and a capacitance circuit configured to include a capacitive element and being connected to the second wiring. | 09-23-2010 |
| 20100237346 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME - A rectifier is formed by forming a first electrode layer, a semiconductor layer and a second electrode layer. A third electrode layer is formed between the first electrode layer and the semiconductor layer, or between the second electrode layer and the semiconductor layer. | 09-23-2010 |
| 20100238704 | SEMICONDUCTOR MEMORY DEVICE, METHOD OF MANUFACTURING THE SAME, AND METHOD OF SCREENING THE SAME - A memory cell comprises a variable resistance film; a first conductive film having one surface contacted with one surface of the variable resistance film; and a second conductive film having one surface contacted with another surface of the variable resistance film. A width of the first conductive film or the second conductive film in a direction orthogonal to a direction that a current flows in the first conductive film or the second conductive film is smaller than a width of the variable resistance film in a direction orthogonal to a direction that a current flows in the variable resistance film. The width of the first conductive film and the second conductive film is smaller than a width of the first line and the second line in a direction orthogonal to a direction that a current flows in the first line and the second line. | 09-23-2010 |
| 20110002156 | SEMICONDUCTOR MEMORY DEVICE - A semiconductor memory device includes a plurality of first wirings; a plurality of second wirings; a plurality of memory cells positioned at respective intersections of the first wirings and the second wirings, each of the memory cells having a variable resistance element and a selective element connected to the variable resistance element in series; a first selection portion selecting the first wiring; a second selection portion selecting the second wiring; and a power source portion applying predetermined selected-wiring-voltages to a selected first wiring being selected by the first selection portion and a selected second wiring being selected by the second selection portion, respectively, and applying predetermined unselected-wiring-voltages to unselected first wirings other than the selected first wiring and unselected second wirings other than the selected second wiring, respectively. A resistance element having a predetermined resistance value is provided between the power source portion and the unselected first and second wirings. | 01-06-2011 |
| 20110026299 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND METHOD OF DATA WRITE/DATA ERASE THEREIN - A nonvolatile semiconductor memory device comprises: a plurality of first lines; a plurality of second lines; a plurality of memory cells each disposed at each of crossing-points of the first lines and the second lines and each comprising a variable resistor and a bi-directional diode; and a voltage control circuit configured to control a voltage of selected one of the first lines, unselected ones of the first lines, selected one of the second lines, and unselected ones of the second lines, respectively. The variable resistor is configured to change its resistance value depending on a polarity of a voltage applied thereto. The voltage control circuit is configured to apply a voltage pulse to the selected one of the first lines and to connect a capacitor of a certain capacitance to one end of the selected one of the second lines. | 02-03-2011 |
