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Norikatsu Takaura, Tokyo JP

Norikatsu Takaura, Tokyo JP

Patent application numberDescriptionPublished
20090014708SEMICONDUCTOR DEVICE - A nonvolatile, sophisticated semiconductor device with a small surface area and a simple structure capable of switching connections between three or more electrodes. In a semiconductor device at least one of the electrodes contains atoms such as copper or silver in the solid electrolyte capable of easily moving within the solid electrolyte, and those electrodes face each other and applying a voltage switches the voltage on and off by generating or annihilating the conductive path between the electrodes. Moreover applying a voltage to a separate third electrode can annihilate the conductive path formed between two electrodes without applying a voltage to the two electrode joined by the conductive path.01-15-2009
20090014770SEMICONDUCTOR DEVICE - A technique that can realize high integration even for multilayered three-dimensional structures at low costs by improving the performance of the semiconductor device having recording or switching functions by employing a device structure that enables high precision controlling of the movement of ions in the solid electrolyte. The semiconductor element of the device is formed as follows; two or more layers are deposited with different components respectively between a pair of electrodes disposed separately in the vertical (z-axis) direction, then a pulse voltage is applied between those electrodes to form a conductive path. The resistance value of the path changes according to an information signal. Furthermore, a region is formed at a middle part of the conductive path. The region is used to accumulate a component that improves the conductivity of the path, thereby enabling the resistance value (rate) to response currently to the information signal. More preferably, an electrode should also be formed at least in either the x-axis or y-axis direction to apply a control voltage to the electrode.01-15-2009
20090039335SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME - On an insulating film (02-12-2009
20090039336SEMICONDUCTOR DEVICE - The performance of a semiconductor device capable of storing information is improved. A memory layer of a memory element is formed by a first layer at a bottom electrode side and a second layer at a top electrode side. The first layer contains 20-70 atom % of at least one element of a first element group of Cu, Ag, Au, Al, Zn, and Cd, contains 3-40 atom % of at least one element of a second element group of V, Nb, Ta, Cr, Mo, W, Ti, Zr, Hf, Fe, Co, Ni, Pt, Pd, Rh, Ir, Ru, Os, and lanthanoid elements, and contains 20-60 atom % of at least one element of a third element group of S, Se, and Te. The second layer contains 5-50 atom % of at least one element of the first element group, 10-50 atom % of at least one element of the second element group, and 30-70 atom % of oxygen.02-12-2009
20090052231SEMICONDUCTOR DEVICE - A semiconductor device capable of high-speed read and has a high data-retention characteristic is provided. In a semiconductor device including a memory array having a plurality of memory cells provided at intersecting points of a plurality of word lines and a plurality of bit lines, where each memory cell includes an information memory section and a select element, when information is programmed by a first pulse (reset operation) for programming information flowing in the bit line and a second pulse (set operation) different from the first pulse and information is read by a third pulse (read operation), current directions of the second pulse and the third pulse are opposite to each other.02-26-2009
20090108247Memory Device - A phase-change memory device including a memory cell having a memory element and a select transistor is improved in heat resistance so that it may be operable at 145° C. or higher.04-30-2009
20090122602SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE - There is achieved a high-integrated and high-speed nonvolatile memory which can stabilize an operation of a phase-change memory for a short operation cycle time. A latch is provided in a write driver. A change to a high-resistance state of a phase-change element is performed per column cycle by a write-enable signal, and a change to a low-resistance state thereof is performed after a pre-charge command is inputted and concurrently with deactivation of a pre-charge signal. Thereby, a write time to a memory cell in which phase-change resistance is changed to a low-resistance state, and a period from a write operation for changing the phase-change resistance to a high-resistance state to a read operation to the above memory cell can be lengthened without extending the column cycle time, so that the stable write operation is achieved.05-14-2009
20090140233NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - A nonvolatile semiconductor memory device having a large storage capacity and stabilized rewriting conditions in which a memory cell includes a nonvolatile recording material layer, a selector element and a semiconductor layer provided between the nonvolatile recording material layer and the selector element and having a thickness ranging from 5 to 200 nm.06-04-2009
20090189137NON-VOLATILE MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME - In a phase change memory, electric property of a diode used as a selection device is extremely important. However, since crystal grain boundaries are present in the film of a diode using polysilicon, it involves a problem that the off leak property varies greatly making it difficult to prevent erroneous reading. For overcoming the problem, the present invention provides a method of controlling the temperature profile of an amorphous silicon in the laser annealing for crystallizing and activating the amorphous silicon thereby controlling the crystal grain boundaries. According to the invention, variation in the electric property of the diode can be decreased and the yield of the phase-change memory can be improved.07-30-2009
20090231913SEMICONDUCTOR DEVICE - There is provided a technique capable of improving speed of a set operation, which controls writing rate in a semiconductor device including a memory cell using a phase-change material. The technique uses means for setting a set-pulse voltage to be applied to the phase-change material to have two steps: the first-step voltage sets a temperature of the phase-change memory to a temperature at which the fastest nucleation is obtained; and the second pulse sets the temperature to a temperature at which the fastest crystal growth is obtained, thereby obtaining solid-phase growth of the phase-change material without melting. Moreover, the technique uses means for controlling the two-step voltage applied to the phase-change memory by a two-step voltage applied to a word line capable of reducing the drain current variation.09-17-2009
20090242868SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A solid electrolyte memory involves a problem that stable rewriting is difficult since the amount of ions in the solid electrolyte and the shape of the electrode are changed by repeating rewriting. In a semiconductor device in which information is stored or the circuit connection is changed by the change of resistance of the solid electrolyte layer, the solid electrolyte layer includes a composition, for example, of Cu—Ta—S and an ion supply layer in adjacent or close therewith as Cu—Ta—O, in which ions supplied from the ion supply layer form a conduction path in the solid electrolyte layer thereby making it possible to store information by the level of the resistance and applying the electric pulse to change the resistance, in which the ion supply layer includes crystals having, for example, a compositional ratio of: Cu—Ta—O=1:2:6 and rewriting operation can be performed stably.10-01-2009
20090250680SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE - With a high-speed nonvolatile phase change memory, reliability in respect of the number of refresh times is enhanced. In a memory cell forming area of a phase change memory using a MISFET as a transistor for selection of memory cells, a phase change material layer of a memory cell comprising a resistor element, using a phase change material, is formed for common use. As a result, variation in shape and a change in composition of the phase change material, caused by isolation of memory cell elements by etching, are reduced, thereby enhancing reliability of memory cells, in respect of the number of refresh times.10-08-2009
20090267047SEMICONDUCTOR MEMORY DEVICE AND MANUFACTURING METHOD THEREOF - The present invention can promote the large capacity, high performance and high reliability of a semiconductor memory device by realizing high-performance of both the semiconductor device and a memory device when the semiconductor memory device is manufactured by stacking a memory device such as ReRAM or the phase change memory and the semiconductor device. After a polysilicon forming a selection device is deposited in an amorphous state at a low temperature, the crystallization of the polysilicon and the activation of impurities are briefly performed with heat treatment by laser annealing. When laser annealing is performed, the recording material located below the silicon subjected to the crystallization is completely covered with a metal film or with the metal film and an insulating film, thereby making it possible to suppress a temperature increase at the time of performing the annealing and to reduce the thermal load of the recording material.10-29-2009
20090302293SEMICONDUCTOR DEVICE - On the same semiconductor substrate 12-10-2009
20100012917SEMICONDUCTOR DEVIC - On an insulating film (01-21-2010
20100032637NONVOLATILE MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME - Provided is a nonvolatile memory device including a phase-change memory configured with cross-point memory cells in which memory elements formed of a phase-change material and selection elements formed with a diode are combined. A memory cell is configured with a memory element formed of a phase-change material and a selection element formed with a diode having a stacked structure of a first polycrystalline silicon film, a second polycrystalline silicon film, and a third polycrystalline silicon film. The memory cells are arranged at intersection points of a plurality of first metal wirings extending along a first direction with a plurality of third metal wirings extending along a second direction orthogonal to the first direction. An interlayer film is formed between adjacent selection elements and between adjacent memory elements, and voids are formed in the interlayer film provided between the adjacent memory elements.02-11-2010
20100044672SEMICONDUCTOR MEMORY - Manufacturing processes for phase change memory have suffered from the problem of chalcogenide material being susceptible to delamination, since this material exhibits low adhesion to high melting point metals and silicon oxide films. Furthermore, chalcogenide material has low thermal stability and hence tends to sublime during the manufacturing process of phase change memory. According to the present invention, conductive or insulative adhesive layers are formed over and under the chalcogenide material layer to enhance its delamination strength. Further, a protective film made up of a nitride film is formed on the sidewalls of the chalcogenide material layer to prevent sublimation of the chalcogenide material layer.02-25-2010
20100058127SEMICONDUCTOR DEVICE - To realize a fast and highly reliable phase-change memory system of low power consumption, a semiconductor device includes: a memory device which includes a first memory array having a first area including a plurality of first memory cells and a second area including a plurality of second memory cells; a controller coupled to the memory device to issue a command to the memory device; and a condition table for storing a plurality of trial writing conditions. The controller performs trial writing in the plurality of second memory cells a plurality of times based on the plurality of trial writing conditions stored in the condition table, and determines writing conditions in the plurality of first memory cells based on a result of the trial writing. The memory device performs writing in the plurality of first memory cells based on the writing conditions instructed from the controller.03-04-2010
20100061132SEMICONDUCTOR STORAGE DEVICE - In a semiconductor storage device such as a phase change memory, a technique which can realize high integration is provided. The semiconductor storage device includes a phase change thin film 03-11-2010
20100072451SEMICONDUCTOR DEVICE - A recording layer 03-25-2010
20100096613SEMICONDUCTOR DEVICE - A phase change memory is formed of a plug buried within a through-hole in an insulating film formed on a semiconductor substrate, an interface layer formed on the insulating film in which the plug is buried, a recording layer formed of a chalcogenide layer formed on the interface layer, and an upper contact electrode formed on the recording layer. The recording layer storing information according to resistance value change is made of chalcogenide material containing indium in an amount range from 20 atomic % to 38 atomic %, germanium in a range from 9 atomic % to 28 atomic %, antimony in a range from 3 atomic % to 18 atomic %, and tellurium in a range from 42 atomic % to 63 atomic %, where the content of germanium larger than or equal to the content of antimony.04-22-2010
20100171087SEMICONDUCTOR DEVICE AND PROCESS FOR PRODUCING THE SAME - In a semiconductor device including a phase change memory element whose memory layer is formed of a phase change material of M (additive element)-Ge (germanium)-Sb (antimony)-Te (tellurium), both of high heat resistance and stable data retention property are achieved. The memory layer has a fine structure with a different composition ratio therein, and an average composition of M07-08-2010
20100182828SEMICONDUCTOR STORAGE DEVICE - There is provided a semiconductor storage device which is capable of further reducing a size of a memory cell, and increasing a storage capacity. Plural memory cells each including a transistor formed on a semiconductor substrate, and a variable resistive device having a resistance value changed by voltage supply and connected between source and drain terminals of the transistor are arranged longitudinally and in an array to configure a three-dimensional memory cell array. A memory cell structure has a double channel structure in which an inside of a switching transistor is filled with a variable resistance element, particularly, a phase change material. The switching transistor is turned off by application of a voltage to increase a channel resistance so that a current flows in the internal phase change material to operate the memory.07-22-2010
20110049454SEMICONDUCTOR DEVICE - In a phase-change memory, an interface layer is inserted between a chalcogenide material layer and a plug. The interface layer is arranged so as not to cover the entire interface of a plug-like electrode. When the plug is formed at an upper part than the chalcogenide layer, the degree of integration is increased. The interface layer is formed by carrying out sputtering using an oxide target, or, by forming a metal film by carrying out sputtering using a metal target followed by oxidizing the metal film in an oxidation atmosphere such as oxygen radical, oxygen plasma, etc.03-03-2011

Patent applications by Norikatsu Takaura, Tokyo JP