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Takashi Maeda, Yokohama-Shi JP

Takashi Maeda, Yokohama-Shi JP

Patent application numberDescriptionPublished
20090201717RESISTANCE-CHANGE MEMORY - A resistance-change memory includes first and second bit lines running in the same direction, a third bit line running parallel to the first and second bit lines, fourth and fifth bit lines running in the same direction, a sixth bit line running parallel to the fourth and fifth bit lines, a first memory element which has one and the other terminals connected to the first and third bit lines, and changes to one of first and second resistance states, a first reference element having one and the other terminals connected to the fourth and sixth bit lines, and set in the first resistance state, a second reference element having one and the other terminals connected to the fifth and sixth bit lines, and set in the second resistance state, and a sense amplifier having first and second input terminals connected to the first and fourth bit lines.08-13-2009
20100124116NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE - Memory strings includes: a first semiconductor layer including a columnar portion extending in a direction perpendicular to a substrate; a first electric charge storage layer formed to surround a side surface of the columnar portion; and a first conductive layer formed to surround the first electric charge storage layer. First selection transistors includes: a second semiconductor layer extending upward from a top surface of the columnar portion; a second electric charge storage layer formed to surround a side surface of the second semiconductor layer; and a second conductive layer formed to surround the second electric charge storage layer. The non-volatile semiconductor storage device further includes a control circuit that causes, prior to reading data from a selected one of the memory strings, electric charges to be accumulated in the second electric charge storage layer of one of the first selection transistors connected to an unselected one of the memory strings.05-20-2010
20100172189NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE - A non-volatile semiconductor storage device includes: a memory string including a plurality of memory cells connected in series; a first selection transistor having one end connected to one end of the memory string; a first wiring having one end connected to the other end of the first selection transistor; a second wiring connected to a gate of the first selection transistor. A control circuit is configured to boost voltages of the second wiring and the first wiring in the erase operation, while keeping the voltage of the first wiring greater than the voltage of the second wiring by a certain potential difference. The certain potential difference is a potential difference that causes a GIDL current.07-08-2010
20100214838NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE - A non-volatile semiconductor storage device includes a control circuit performing an erase operation to erase data from a selected one of memory transistors. The control circuit applies a first voltage to the other end of selected one of selection transistors, causes the selected one of the selection transistors to turn on, and causes any one of the memory transistors to turn on that is closer to the selection transistor than the selected one of the memory transistors. The control circuit also applies a second voltage lower than the first voltage to a gate of the selected one of the memory transistors. Such a potential difference between the first voltage and the second voltage causing a change in electric charges in the electric charge storage layer.08-26-2010
20100232224NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE - A memory cell array has plural memory strings arranged therein, each of which including a plurality of electrically-rewritable memory transistors and selection transistors. Each memory string includes a body semiconductor layer including four or more columnar portions, and a joining portion formed to join the lower ends thereof. An electric charge storage layer is formed to surround a side surface of the columnar portions. A first conductive layer is formed to surround a side surface of the columnar portions as well as the electric charge storage layer. A plurality of second conductive layers are formed on side surfaces of the joining portion via an insulation film, and function as control electrodes of a plurality of back-gate transistors formed at a respective one of the joining portions.09-16-2010
20110063916NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE - At least some of the memory transistors included in a first memory string are commonly connected to first conductive layers that are connected to at least some of the memory transistors included in a second memory string connected to the same third and fourth conductive layers as the first memory string. At least one of either the memory transistors or the back-gate transistor in the first memory string and at least one of either the memory transistors or the back-gate transistor in the second memory string are connected to the independent first or fifth conductive layers, respectively.03-17-2011
20120176836NON-VOLATILE SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a non-volatile semiconductor memory device comprises memory strings. Each memory string comprises a semiconductor layer, control gates, a first selection gate, and a second selection gate. A semiconductor layer comprises a pair of pillar portions which extend in a vertical direction to a substrate, and a coupling portion formed to couple the pair of pillar portions. Control gates orthogonally intersect one of the pair of pillar portions or the other of the pair of pillar portions. A first selection gate orthogonally intersects one of the pair of pillar portions and is formed above the control gates. A second selection gate orthogonally intersects the other of the pair of pillar portions, is formed above the control gates, and is on the same level as the first selection gate as well as integrated with the first selection gate.07-12-2012
20120218821NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE - A non-volatile semiconductor storage device includes: a memory string including a plurality of memory cells connected in series; a first selection transistor having one end connected to one end of the memory string; a first wiring having one end connected to the other end of the first selection transistor; a second wiring connected to a gate of the first selection transistor. A control circuit is configured to boost voltages of the second wiring and the first wiring in the erase operation, while keeping the voltage of the first wiring greater than the voltage of the second wiring by a certain potential difference. The certain potential difference is a potential difference that causes a GIDL current.08-30-2012

Patent applications by Takashi Maeda, Yokohama-Shi JP