Patents by Inventor Hiroaki Iuchi
Hiroaki Iuchi 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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Publication number: 20240071819Abstract: A variety of applications can include apparatus having a memory device structured with a three-dimensional array of memory cells and one or more vertical metal contacts extending through levels of the memory device, where the one or more vertical metal contacts are formed with reduced stress. Each of the one or more vertical metal contacts can be constructed by forming a liner on walls of an opening in a dielectric, where the opening extends through the levels for the memory device, and forming a metal composition adjacent the liner and filling the opening with the metal composition. The liner can be removed from at least a portion of the walls of the dielectric, where the liner has a composition correlated to the metal composition such that removal of the liner reduces stress on the metal composition.Type: ApplicationFiled: August 15, 2023Publication date: February 29, 2024Inventors: Chandra S. Tiwari, Jivaan Kishore Jhothiraman, Rutuparna Narulkar, Nayan Chakravarty, Pengyuan Zheng, Hiroaki Iuchi
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Patent number: 9837431Abstract: A vertical memory device including dual memory cells per level in each memory opening can have dielectric separator dielectric structures that protrude into a facing pair of sidewalls of the memory stack structure within the memory opening. A pair of inactive sections of a vertical semiconductor channel facing the dielectric separator dielectric structures is laterally recessed from control gate electrodes. Control of the threshold voltage of such a vertical memory device can be enhanced because of the dielectric separator dielectric structures. The fringe field from the control gate electrodes is weaker due to an increased distance between the control gate electrodes and the inactive sections of the vertical semiconductor channel. The memory stack structure can have concave sidewalls that contact the dielectric separator dielectric structures and convex sidewalls that protrude toward the control gate electrodes.Type: GrantFiled: January 28, 2016Date of Patent: December 5, 2017Assignee: SANDISK TECHNOLOGIES LLCInventors: Masatoshi Nishikawa, Hiroaki Iuchi, Masafumi Miyamoto
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Patent number: 9818798Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Each gate is formed over the gate dielectric and a base that extends horizontally at least partially between adjacent pillars. The base is formed with notches filled with the gate dielectric. The select device is fabricated using a conformally deposited base dielectric material and conformal hard mask layer that is formed with a larger bottom thickness than horizontal thickness. The base thickness is defined by the deposition thickness, rather than an uncontrolled etch back.Type: GrantFiled: June 3, 2016Date of Patent: November 14, 2017Assignee: SanDisk Technologies LLCInventors: Naoki Takeguchi, Hiroaki Iuchi
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Patent number: 9728499Abstract: A trench can be formed through a stack of alternating plurality of first material layers and second material layers. A dielectric material liner and a trench fill material portion can be formed in the trench. The dielectric material liner and portions of first material layer can be simultaneously etched to form laterally-extending cavities having level-dependent lateral extents. A set of stepped surfaces can be formed by removing unmasked portions of the second material layers. Alternately, an alternating sequence of processing steps including vertical etch processes and lateral recess processes can be employed to laterally recess second material layers and to form laterally-extending cavities having level-dependent lateral extents. Lateral cavities can be simultaneously formed in multiple levels such that levels having laterally-extending cavities of a same lateral extent are offset across multiple integrated cavities.Type: GrantFiled: November 26, 2014Date of Patent: August 8, 2017Assignee: SANDISK TECHNOLOGIES LLCInventors: Seiji Shimabukuro, Hiroaki Iuchi, Michiaki Sano, Naoki Takeguchi
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Patent number: 9691778Abstract: Contact openings extending to sacrificial layers located at different depths can be formed by sequentially exposing a greater number of openings in a mask layer by iterative alternation of trimming of a slimming layer over the mask layer and an anisotropic etch that recesses pre-existing contact openings by one level. In one embodiment, pairs of an electrically conductive via contact and electrically conductive electrodes can be simultaneously formed as integrated line and via structures. In another embodiment, encapsulated unfilled cavities can be formed in the contact openings by non-conformal deposition of a material layer, electrically conductive electrodes can be formed by replacement of portions of the sacrificial layers, and the electrically conductive via contacts can be subsequently formed on the electrically conductive electrodes. Electrically conductive via contacts extending to electrically conductive electrodes located at different level can be provided with self-aligned insulating liner.Type: GrantFiled: June 22, 2016Date of Patent: June 27, 2017Assignee: SANDISK TECHNOLOGIES LLCInventors: Keisuke Izumi, Hiroaki Iuchi, Ryo Taura, Kentaro Sera, Akio Yanai
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Publication number: 20170148805Abstract: A vertical memory device including dual memory cells per level in each memory opening can have dielectric separator dielectric structures that protrude into a facing pair of sidewalls of the memory stack structure within the memory opening. A pair of inactive sections of a vertical semiconductor channel facing the dielectric separator dielectric structures is laterally recessed from control gate electrodes. Control of the threshold voltage of such a vertical memory device can be enhanced because of the dielectric separator dielectric structures. The fringe field from the control gate electrodes is weaker due to an increased distance between the control gate electrodes and the inactive sections of the vertical semiconductor channel. The memory stack structure can have concave sidewalls that contact the dielectric separator dielectric structures and convex sidewalls that protrude toward the control gate electrodes.Type: ApplicationFiled: January 28, 2016Publication date: May 25, 2017Inventors: Masatoshi NISHIKAWA, Hiroaki IUCHI, Masafumi MIYAMOTO
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Patent number: 9601508Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. After formation of a memory opening, all surfaces of the memory opening are provided as silicon oxide surfaces by formation of at least one silicon oxide portion. A silicon nitride layer is formed in the memory opening. After formation of a memory stack structure, backside recesses can be formed employing the silicon oxide portions as an etch stop. The silicon oxide portions can be subsequently removed employing the silicon nitride layer as an etch stop. Physically exposed portions of the silicon nitride layer can be removed selective to the memory stack structure. Damage to the outer layer of the memory stack structure can be minimized or eliminated by successive use of etch stop structures. Electrically conductive layers can be subsequently formed in the backside recesses.Type: GrantFiled: October 23, 2015Date of Patent: March 21, 2017Assignee: SANDISK TECHNOLOGIES LLCInventors: Jongsun Sel, Chan Park, Atsushi Suyama, Frank Yu, Hiroyuki Ogawa, Ryoichi Honma, Kensuke Yamaguchi, Hiroaki Iuchi, Naoki Takeguchi, Tuan Pham, Kiyohiko Sakakibara, Jiao Chen
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Publication number: 20160315095Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. After formation of a memory opening, all surfaces of the memory opening are provided as silicon oxide surfaces by formation of at least one silicon oxide portion. A silicon nitride layer is formed in the memory opening. After formation of a memory stack structure, backside recesses can be formed employing the silicon oxide portions as an etch stop. The silicon oxide portions can be subsequently removed employing the silicon nitride layer as an etch stop. Physically exposed portions of the silicon nitride layer can be removed selective to the memory stack structure. Damage to the outer layer of the memory stack structure can be minimized or eliminated by successive use of etch stop structures. Electrically conductive layers can be subsequently formed in the backside recesses.Type: ApplicationFiled: October 23, 2015Publication date: October 27, 2016Inventors: Jongsun Sel, Chan Park, Atsushi Suyama, Frank Yu, Hiroyuki Ogawa, Ryoichi Honma, Kensuke Yamaguchi, Hiroaki Iuchi, Naoki Takeguchi, Tuan Pham, Kiyohiko Sakakibara, Jiao Chen
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Publication number: 20160307912Abstract: Contact openings extending to sacrificial layers located at different depths can be formed by sequentially exposing a greater number of openings in a mask layer by iterative alternation of trimming of a slimming layer over the mask layer and an anisotropic etch that recesses pre-existing contact openings by one level. In one embodiment, pairs of an electrically conductive via contact and electrically conductive electrodes can be simultaneously formed as integrated line and via structures. In another embodiment, encapsulated unfilled cavities can be formed in the contact openings by non-conformal deposition of a material layer, electrically conductive electrodes can be formed by replacement of portions of the sacrificial layers, and the electrically conductive via contacts can be subsequently formed on the electrically conductive electrodes. Electrically conductive via contacts extending to electrically conductive electrodes located at different level can be provided with self-aligned insulating liner.Type: ApplicationFiled: June 22, 2016Publication date: October 20, 2016Inventors: Keisuke Izumi, Hiroaki Iuchi, Ryo Taura, Kentaro Sera, Akio Yanai
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Publication number: 20160284765Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Each gate is formed over the gate dielectric and a base that extends horizontally at least partially between adjacent pillars. The base is formed with notches filled with the gate dielectric. The select device is fabricated using a conformally deposited base dielectric material and conformal hard mask layer that is formed with a larger bottom thickness than horizontal thickness. The base thickness is defined by the deposition thickness, rather than an uncontrolled etch back.Type: ApplicationFiled: June 3, 2016Publication date: September 29, 2016Applicant: SanDisk Technologies LLCInventors: Naoki Takeguchi, Hiroaki Iuchi
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Patent number: 9401309Abstract: Contact openings extending to sacrificial layers located at different depths can be formed by sequentially exposing a greater number of openings in a mask layer by iterative alternation of trimming of a slimming layer over the mask layer and an anisotropic etch that recesses pre-existing contact openings by one level. In one embodiment, pairs of an electrically conductive via contact and electrically conductive electrodes can be simultaneously formed as integrated line and via structures. In another embodiment, encapsulated unfilled cavities can be formed in the contact openings by non-conformal deposition of a material layer, electrically conductive electrodes can be formed by replacement of portions of the sacrificial layers, and the electrically conductive via contacts can be subsequently formed on the electrically conductive electrodes. Electrically conductive via contacts extending to electrically conductive electrodes located at different level can be provided with self-aligned insulating liner.Type: GrantFiled: August 26, 2014Date of Patent: July 26, 2016Assignee: SANDISK TECHNOLOGIES LLCInventors: Keisuke Izumi, Naohito Yanagida, Michiaki Sano, Takehiro Yamazaki, Hiroaki Iuchi, Akio Yanai, Genta Mizuno, Minoru Yamaguchi
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Patent number: 9362338Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Each gate is formed over the gate dielectric and a base that extends horizontally at least partially between adjacent pillars. The base is formed with notches filled with the gate dielectric. The select device is fabricated using a conformally deposited base dielectric material and conformal hard mask layer that is formed with a larger bottom thickness than horizontal thickness. The base thickness is defined by the deposition thickness, rather than an uncontrolled etch back.Type: GrantFiled: March 3, 2014Date of Patent: June 7, 2016Assignee: SanDisk Technologies Inc.Inventors: Naoki Takeguchi, Hiroaki Iuchi
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Publication number: 20160148835Abstract: A trench can be formed through a stack of alternating plurality of first material layers and second material layers. A dielectric material liner and a trench fill material portion can be formed in the trench. The dielectric material liner and portions of first material layer can be simultaneously etched to form laterally-extending cavities having level-dependent lateral extents. A set of stepped surfaces can be formed by removing unmasked portions of the second material layers. Alternately, an alternating sequence of processing steps including vertical etch processes and lateral recess processes can be employed to laterally recess second material layers and to form laterally-extending cavities having level-dependent lateral extents. Lateral cavities can be simultaneously formed in multiple levels such that levels having laterally-extending cavities of a same lateral extent are offset across multiple integrated cavities.Type: ApplicationFiled: November 26, 2014Publication date: May 26, 2016Inventors: Seiji SHIMABUKURO, Hiroaki IUCHI, Michiaki SANO, Naoki TAKEGUCHI
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Patent number: 9281314Abstract: Non-volatile storage devices and methods for fabricating non-volatile storage device are described. Sidewalls of the memory cells and their associated word line may be covered with silicon oxide. Silicon nitride covers the silicon oxide adjacent to the word lines, which may provide protection for the word lines during fabrication. However, silicon nitride can trap charges, which can degrade operation if the trapped charges are near a charge trapping region of a memory cell. Thus, the silicon nitride does not cover the silicon oxide adjacent to charge storage regions of the memory cells, which can improve device operation. For example, memory cell current may be increased. Techniques for forming such a device are also disclosed. One aspect includes a method that uses a sacrificial material to control formation of a silicon nitride layer when forming a memory device.Type: GrantFiled: October 10, 2014Date of Patent: March 8, 2016Assignee: SanDisk Technologies Inc.Inventors: Takashi Kashimura, Xiaolong Hu, Sayako Nagamine, Yusuke Yoshida, Hiroaki Iuchi, Akira Nakada, Kazutaka Yoshizawa
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Publication number: 20160064281Abstract: Contact openings extending to sacrificial layers located at different depths can be formed by sequentially exposing a greater number of openings in a mask layer by iterative alternation of trimming of a slimming layer over the mask layer and an anisotropic etch that recesses pre-existing contact openings by one level. In one embodiment, pairs of an electrically conductive via contact and electrically conductive electrodes can be simultaneously formed as integrated line and via structures. In another embodiment, encapsulated unfilled cavities can be formed in the contact openings by non-conformal deposition of a material layer, electrically conductive electrodes can be formed by replacement of portions of the sacrificial layers, and the electrically conductive via contacts can be subsequently formed on the electrically conductive electrodes. Electrically conductive via contacts extending to electrically conductive electrodes located at different level can be provided with self-aligned insulating liner.Type: ApplicationFiled: August 26, 2014Publication date: March 3, 2016Inventors: Keisuke Izumi, Naohito Yanagida, Michiaki Sano, Takehiro Yamazaki, Hiroaki Iuchi, Akio Yanai, Genta Mizuno, Minoru Yamaguchi
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Patent number: 9236392Abstract: Contact openings extending to sacrificial layers located at different depths can be formed by sequentially exposing a greater number of openings in a mask layer by iterative alternation of trimming of a slimming layer over the mask layer and an anisotropic etch that recesses pre-existing contact openings by one level. In one embodiment, pairs of an electrically conductive via contact and electrically conductive electrodes can be simultaneously formed as integrated line and via structures. In another embodiment, encapsulated unfilled cavities can be formed in the contact openings by non-conformal deposition of a material layer, electrically conductive electrodes can be formed by replacement of portions of the sacrificial layers, and the electrically conductive via contacts can be subsequently formed on the electrically conductive electrodes. Electrically conductive via contacts extending to electrically conductive electrodes located at different level can be provided with self-aligned insulating liner.Type: GrantFiled: August 26, 2014Date of Patent: January 12, 2016Assignee: SANDISK TECHNOLOGIES INC.Inventors: Keisuke Izumi, Hiroaki Iuchi, Ryo Taura, Kentaro Sera, Akio Yanai
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Publication number: 20150249112Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating such a memory are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Each gate is formed over the gate dielectric and a base that extends horizontally at least partially between adjacent pillars. The base is formed with notches that are filled with the gate dielectric. The select device is fabricated using a conformally deposited base dielectric material and conformal hard mask layer that is formed with a larger bottom thickness than horizontal thickness. The hard mask permits the base thickness to be defined by the deposition thickness, rather than an uncontrolled etch back.Type: ApplicationFiled: March 3, 2014Publication date: September 3, 2015Applicant: SanDisk 3D LLCInventors: Naoki Takeguchi, Hiroaki Iuchi
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Patent number: 9123577Abstract: Electrical isolation in non-volatile memory is provided by air gaps formed using sacrificial films of differing etch rates. A high etch rate material is formed in an isolation trench. Flowable chemical vapor deposition processes are used to form high etch rate films, and curing is performed to increase their etch rate. A low etch material is formed over the high etch rate material and provides a controlled etch back between charge storage regions in a row direction. A discrete low etch rate layer can be formed or the high etch rate material can be oxidized to form an upper region with a lower etch rate. A controlled etch back enables formation of a wrap-around dielectric and control gate structure in the row direction with minimized variability in the dimensions of the structures. At least a portion of the high etch rate material is removed to form air gaps for isolation.Type: GrantFiled: December 12, 2012Date of Patent: September 1, 2015Assignee: SanDisk Technologies Inc.Inventors: Hitomi Fujimoto, Hiroaki Iuchi, Ming Tian, Daisuke Maekawa
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Patent number: 8937011Abstract: Techniques disclosed herein may achieve crack free filling of structures. A flowable film may substantially fill gaps in a structure and extend over a base in an open area adjacent to the structure. The top surface of the flowable film in the open area may slope down and may be lower than top surfaces of the structure. A capping layer having compressive stress may be formed over the flowable film. The bottom surface of the capping layer in the open area adjacent to the structure is lower than the top surfaces of the lines and may be formed on the downward slope of the flowable film. The flowable film is cured after forming the capping layer, which increases tensile stress of the flowable film. The compressive stress of the capping layer counteracts the tensile stress of the flowable film, which may prevent a crack from forming in the base.Type: GrantFiled: January 15, 2013Date of Patent: January 20, 2015Assignee: SanDisk 3D LLCInventors: Hiroaki Iuchi, Hitomi Fujimoto, Chao Feng Yeh
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Patent number: 8802561Abstract: Techniques disclosed herein prevent wire flaking (collapse). One aspect is an improved way of forming wires over trenches, which may be located in a hookup region of a 3D memory array, and may be used to form electrical connections between conductive lines in the memory array and drivers. The trenches are formed between CMP dummy structures. The trenches are partially filled with a flowable oxide film, which leaves a gap in the trench that is at least as wide as the total pitch of the wires to be formed. A capping layer is formed over the flowable film. After forming a conductive layer over the dielectric layer, the conductive layer is etched to form conductive wires. Some of the capping layer, as well as the CMP dummy structures may be removed. Thus, the conductive wires may be at least temporarily supported by lines of material formed from the capping layer.Type: GrantFiled: April 12, 2013Date of Patent: August 12, 2014Assignee: SanDisk 3D LLCInventors: Chao Feng Yeh, Hiroaki Iuchi, Hitomi Fujimoto, Hisayuki Nozawa