Patents by Inventor Satoru Hanzawa
Satoru Hanzawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8737116Abstract: In a semiconductor device including a memory cell array formed of memory cells using a storage element by a variable resistor and a select transistor, a buffer cell is arranged between a sense amplifier and the memory cell array and between a word driver and the memory cell array. The resistive storage element in the memory cell is connected to a bit-line via a contact formed above the resistive storage element. Meanwhile, in the buffer cell, the contact is not formed above the resistive storage element, and a state of being covered with an insulator is kept upon processing the contact in the memory cell. By such a processing method, exposure and sublimation of a chalcogenide film used in the resistive storage element can be avoided.Type: GrantFiled: June 25, 2013Date of Patent: May 27, 2014Assignee: Renesas Electronics CorporationInventors: Satoru Hanzawa, Fumihiko Nitta, Nozomu Matsuzaki, Toshihiro Tanaka
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Patent number: 8730717Abstract: A semiconductor device has multiple memory cell groups arranged at intersections between multiple word lines and multiple bit lines intersecting the word lines. The memory cell groups each have first and second memory cells connected in series. Each of the first and the second memory cells has a select transistor and a resistive storage device connected in parallel. The gate electrode of the select transistor in the first memory cell is connected with a first gate line, and the gate electrode of the select transistor in the second memory cell is connected to a second gate line. A first circuit block for driving the word lines (word driver group WDBK) is arranged between a second circuit block for driving the first and second gate lines (phase-change-type chain cell control circuit PCCCTL) and multiple memory cell groups (memory cell array MA).Type: GrantFiled: May 9, 2011Date of Patent: May 20, 2014Assignee: Hitachi, Ltd.Inventors: Satoru Hanzawa, Yoshitaka Sasago
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Patent number: 8711637Abstract: In a phase change memory, when M bit (8 bits=1 byte) data is written, erase operation and program operation are performed in units of n bit (M>n) data. Further, when M bit data is written, program operation is performed in units of the n bit (M>n) data. Further, when M bit data is read from the memory cell, read operation is performed in units of the n bit (M>n) data. For example, when the data is written into to the phase change memory, the data is not overwritten but program is performed after once erasing the target memory cell. The data size for erasure and the data size for program are made equal. Erase and program operation are performed only for the demanded data size.Type: GrantFiled: November 18, 2011Date of Patent: April 29, 2014Assignee: Hitachi, Ltd.Inventors: Seiji Miura, Satoru Hanzawa
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Publication number: 20140103287Abstract: Disclosed are a semiconductor storage device and a manufacturing method. The storage device has: a substrate; a first word line above the substrate; a first laminated body above the first word line and having N+1 first inter-gate insulating layers and N first semiconductor layers alternately laminated; a first bit line above the laminated body and extending in a direction that intersects the first word line; a first gate insulating layer on side surfaces of the first inter-gate insulating layers and the first semiconductor layers; a first channel layer on the side surface of the first gate insulating layer; and a first variable resistance material layer on the side surface of the first channel layer. The first variable resistance material layer is in a region where the first word line and the first bit line intersect. A polysilicon diode is used as a selection element.Type: ApplicationFiled: October 6, 2013Publication date: April 17, 2014Applicant: Hitachi, Ltd.Inventors: Yoshitaka Sasago, Akio Shima, Satoru Hanzawa, Takashi Kobayashi, Masaharu Kinoshita, Norikatsu Takaura
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Patent number: 8699262Abstract: Adverse effects of a parasitic resistance and a parasitic capacitance of a driver circuit to a memory cell causes problems of thermal disturbance to a not-selected cell, unevenness of application voltage, degradation of a memory element in reading. A capacitor (C) is provided above or beneath a memory cell (MC) that includes a memory element to which a current write memory information and a selection element connected to the memory element. A charge stored in this capacitor writes to the memory element.Type: GrantFiled: October 11, 2011Date of Patent: April 15, 2014Assignee: Hitachi, Ltd.Inventors: Takao Watanabe, Satoru Hanzawa, Yoshitaka Sasago
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Publication number: 20140056062Abstract: A semiconductor storage apparatus provides a large capacity phase-change memory possessing high speed operation, low electrical current, and high-reliability. During the period that a read-out start signal is activated in the memory region control circuit and the block of pairs of sense-latch and write driver is performing the verify read in the upper section memory region; the write enable signals in the memory region control circuit are activated and the block of pairs of sense-latch and write driver perform rewrite operation of the data in the lower section memory region. This type of operation allows cancelling out the time required for the verify read and the time required for the time-division write operation by performing the verify read in one memory region, while performing time-division rewrite in other memory region, to achieve both higher reliability rewrite operation along with suppressing the rewrite operation peak electrical current.Type: ApplicationFiled: November 1, 2013Publication date: February 27, 2014Applicant: Hitachi, Ltd.Inventor: Satoru HANZAWA
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Patent number: 8634257Abstract: A semiconductor storage device crystallizes variable resistive element material layers arranged on side surfaces of multiple semiconductor layers in a stacked structure concurrently by applying a first current to any one of semiconductor layers in the stacked structure, and thereafter applies a second current to semiconductor layers other than a semiconductor layer to which the first current was applied.Type: GrantFiled: May 8, 2012Date of Patent: January 21, 2014Assignee: Hitachi, Ltd.Inventors: Satoru Hanzawa, Hiroyuki Minemura
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Patent number: 8614922Abstract: A semiconductor storage apparatus provides a large capacity phase-change memory possessing high speed operation, low electrical current, and high-reliability. During the period that a read-out start signal is activated in the memory region control circuit, and the block of pairs of sense-latch and write driver is performing the verify read in the upper section memory region, the write enable signals in the memory region control circuit are activated and the block of pairs of sense-latch and write driver performs rewrite operation of the data in the lower section memory region. This type of operation allows cancelling out the time required for the verify read and the time required for the time-division write operation by performing the verify read in one memory region, while performing time-division rewrite in other memory region, to achieve both higher reliability rewrite operation along with suppressing the rewrite operation peak electrical current.Type: GrantFiled: December 15, 2011Date of Patent: December 24, 2013Assignee: Hitachi, Ltd.Inventor: Satoru Hanzawa
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Publication number: 20130277635Abstract: In a semiconductor device including a memory cell array formed of memory cells using a storage element by a variable resistor and a select transistor, a buffer cell is arranged between a sense amplifier and the memory cell array and between a word driver and the memory cell array. The resistive storage element in the memory cell is connected to a bit-line via a contact formed above the resistive storage element. Meanwhile, in the buffer cell, the contact is not formed above the resistive storage element, and a state of being covered with an insulator is kept upon processing the contact in the memory cell. By such a processing method, exposure and sublimation of a chalcogenide film used in the resistive storage element can be avoided.Type: ApplicationFiled: June 25, 2013Publication date: October 24, 2013Inventors: Satoru HANZAWA, Fumihiko NITTA, Nozomu MATSUZAKI, Toshihiro TANAKA
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Patent number: 8563961Abstract: Disclosed are a semiconductor storage device and a method for manufacturing the semiconductor storage device, whereby the bit cost of memory using a variable resistance material is reduced.Type: GrantFiled: December 13, 2010Date of Patent: October 22, 2013Assignee: Hitachi, Ltd.Inventors: Yoshitaka Sasago, Akio Shima, Satoru Hanzawa, Takashi Kobayashi, Masaharu Kinoshita, Norikastsu Takaura
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Patent number: 8482997Abstract: A highly reliable large capacity phase change memory module is realized. A semiconductor device according to the present invention includes a memory array having a structure in which a storage layer using a chalcogenide material and a memory cell constituted of a diode are stacked, and an initialization condition and a rewriting condition are changed in accordance with the layer where a selected memory cell is located. A current mirror circuit is selected in accordance with an operation, and at the same time, the initialization condition and the rewriting condition (here, reset condition) are changed in accordance with the operation by a control mechanism of the reset current in a voltage selection circuit and a current mirror circuit.Type: GrantFiled: February 5, 2012Date of Patent: July 9, 2013Assignee: Hitachi, Ltd.Inventors: Satoru Hanzawa, Hitoshi Kume, Motoyasu Terao, Tomonori Sekiguchi, Makoto Saen
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Patent number: 8482961Abstract: In a semiconductor device including a memory cell array formed of memory cells using a storage element by a variable resistor and a select transistor, a buffer cell is arranged between a sense amplifier and the memory cell array and between a word driver and the memory cell array. The resistive storage element in the memory cell is connected to a bit-line via a contact formed above the resistive storage element. Meanwhile, in the buffer cell, the contact is not formed above the resistive storage element, and a state of being covered with an insulator is kept upon processing the contact in the memory cell. By such a processing method, exposure and sublimation of a chalcogenide film used in the resistive storage element can be avoided.Type: GrantFiled: April 25, 2012Date of Patent: July 9, 2013Assignee: Renesas Electronics CorporationInventors: Satoru Hanzawa, Fumihiko Nitta, Nozomu Matsuzaki, Toshihiro Tanaka
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Publication number: 20130141968Abstract: The purpose of the present invention is to improve a rewriting transmission rate and reliability of a phase change memory. To attain the purpose, a plurality of phase change memory cells (SMC or USMC) which are provided in series between a word line (2) and a bit line (3) and have a selection element and a storage element that are parallel connected with each other are entirely set, and after that, a part of the cells corresponding to a data pattern is reset. Alternatively, the reverse of the operation is carried out.Type: ApplicationFiled: August 26, 2011Publication date: June 6, 2013Inventors: Yoshitaka Sasago, Hiroyuki Minemura, Takashi Kobayashi, Toshimichi Shintani, Satoru Hanzawa, Masaharu Kinoshita
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Patent number: 8456940Abstract: A phase change memory capable of highly reliable operations is provided. A semiconductor device has a memory array having a structure in which memory cells are stacked including memory layers using a chalcogenide material and diodes, and initialization conditions and write conditions are changed according to the layer in which a selected memory cell is positioned. The initialization conditions and write conditions (herein, reset conditions) are changed according to the operation by selecting a current mirror circuit according to the operation and by a control mechanism of a reset current in a voltage select circuit and the current mirror circuit.Type: GrantFiled: December 6, 2011Date of Patent: June 4, 2013Assignee: Hitachi, Ltd.Inventors: Satoru Hanzawa, Hitoshi Kume
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Patent number: 8427865Abstract: 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.Type: GrantFiled: April 5, 2012Date of Patent: April 23, 2013Assignee: Hitachi, Ltd.Inventors: Akio Shima, Yoshitaka Sasago, Masaharu Kinoshita, Toshiyuki Mine, Norikatsu Takaura, Takahiro Morikawa, Kenzo Kurotsuchi, Satoru Hanzawa
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Patent number: 8319204Abstract: A recording layer 52 made of a chalcogenide material which stores a high-resistance state of a high electrical resistance value and a low-resistance state of a low electrical resistance value is used as a memory element RM in a memory cell region, and it is formed so that a concentration of Ga or In of a first layer 52a positioned on a lower electrode TP side of the recording layer 52 is higher than the corresponding concentration of a second layer 52b positioned on an upper electrode 53 side. For example, the recording layer is formed so that a content of Ga or In of the second layer is 5 atomic % or more smaller than that of the first layer. Also, a circuit which can reverse the voltage polarity between the upper electrode and the lower electrode in a set operation and a reset operation is provided.Type: GrantFiled: July 21, 2006Date of Patent: November 27, 2012Assignee: Renesas Electronics CorporationInventors: Motoyasu Terao, Satoru Hanzawa, Takahiro Morikawa, Kenzo Kurotsuchi, Riichiro Takemura, Norikatsu Takaura, Nozomu Matsuzaki
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Publication number: 20120287697Abstract: A semiconductor storage device crystallizes variable resistive element material layers arranged on side surfaces of multiple semiconductor layers in a stacked structure concurrently by applying a first current to any one of semiconductor layers in the stacked structure, and thereafter applies a second current to semiconductor layers other than a semiconductor layer to which the first current was applied.Type: ApplicationFiled: May 8, 2012Publication date: November 15, 2012Inventors: SATORU HANZAWA, Hiroyuki Minemura
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Publication number: 20120268981Abstract: In a semiconductor device including a memory cell array formed of memory cells using a storage element by a variable resistor and a select transistor, a buffer cell is arranged between a sense amplifier and the memory cell array and between a word driver and the memory cell array. The resistive storage element in the memory cell is connected to a bit-line via a contact formed above the resistive storage element. Meanwhile, in the buffer cell, the contact is not formed above the resistive storage element, and a state of being covered with an insulator is kept upon processing the contact in the memory cell. By such a processing method, exposure and sublimation of a chalcogenide film used in the resistive storage element can be avoided.Type: ApplicationFiled: April 25, 2012Publication date: October 25, 2012Inventors: SATORU HANZAWA, Fumihiko Nitta, Nozomu Matsuzaki, Toshihiro Tanaka
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Patent number: 8289764Abstract: A highly-reliable, highly-integrated large-capacity phase-change memory is achieved. For this purpose, for example, memory tiles MT0, MT1 are provided respectively at points of intersection of global bit line GBL0 and global word lines GWL00B, GWL01B. Word lines WL000 of MT0, MT1 are commonly connected to an output from a word-line driving circuit WD0 which is controlled by GWL00B, and word lines WL001 of MT0, MT1 are commonly connected to an output from a word-line driving circuit WD1 controlled by GWL01B. For example, when WD0 is activated in accordance with a rewrite operation, an output from WD0 is connected to GBL0 via any one of four memory cells MC00, MC01 connected to WL000 of MT0, MT1.Type: GrantFiled: December 7, 2009Date of Patent: October 16, 2012Assignee: Hitachi, Ltd.Inventor: Satoru Hanzawa
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Publication number: 20120248399Abstract: Disclosed are a semiconductor storage device and a method for manufacturing the semiconductor storage device, whereby the bit cost of memory using a variable resistance material is reduced.Type: ApplicationFiled: December 13, 2010Publication date: October 4, 2012Inventors: Yoshitaka Sasago, Akio Shima, Satoru Hanzawa, Takashi Kobayashi, Masaharu Kinoshita, Norikastsu Takaura