Patents by Inventor Tomohiko Kitajima
Tomohiko Kitajima 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: 11574924Abstract: Embodiments of the present disclosure provide an apparatus and methods for forming stair-like structures with accurate profiles and dimension control for manufacturing three dimensional (3D) stacked memory cell semiconductor devices. In one embodiment, a memory cell device includes a film stack comprising alternating pairs of dielectric layers and conductive structures horizontally formed on a substrate, and an opening formed in the film stack, wherein the opening is filled with a metal dielectric layer, a multi-layer structure and a center filling layer, wherein the metal dielectric layer in the opening is interfaced with the conductive structure.Type: GrantFiled: March 26, 2021Date of Patent: February 7, 2023Assignee: Applied Materials, Inc.Inventors: Changseok Kang, Tomohiko Kitajima
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Publication number: 20230012819Abstract: Three-dimensional dynamic random-access memory (3D DRAM) structures and methods of formation of same are provided herein. In some embodiments, a 3D DRAM stack can include alternating silicon (Si) layers and silicon germanium (SiGe) layers. Each of the Si layers may have a height greater than a height of each of the SiGe layers. Methods and systems for formation of such structures are further provided.Type: ApplicationFiled: July 8, 2022Publication date: January 19, 2023Inventors: John Byron Tolle, Tomohiko Kitajima, Thomas John Kirschenheiter, Patricia M. Liu, Zuoming Zhu, Joe Margetis, Fredrick David Fishburn, Abdul Wahab Mohammed, Gill Yong Lee
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Patent number: 11545504Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.Type: GrantFiled: April 12, 2021Date of Patent: January 3, 2023Assignee: APPLIED MATERIALS, INC.Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy
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Patent number: 11515170Abstract: Methods of etching film stacks to form gaps of uniform width are described. A film stack is etched through a hardmask. A conformal liner is deposited in the gap. The bottom of the liner is removed. The film stack is selectively etched relative to the liner. The liner is removed. The method may be repeated to a predetermined depth.Type: GrantFiled: December 30, 2020Date of Patent: November 29, 2022Assignee: APPLIED MATERIALS, INC.Inventors: Shishi Jiang, Pramit Manna, Bo Qi, Abhijit Basu Mallick, Rui Cheng, Tomohiko Kitajima, Harry S. Whitesell, Huiyuan Wang
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Publication number: 20220367560Abstract: Memory devices and methods of manufacturing memory devices are provided. The device and methods described decrease the resistivity of word lines by forming word lines comprising low resistivity materials. The low resistivity material has a resistivity in a range of from 5 ??cm to 100 ??cm. Low resistivity materials may be formed by recessing the word line and selectively growing the low resistivity materials in the recessed portion of the word line. Alternatively, low resistivity materials may be formed by depositing a metal layer and silicidating the metal in the word line region and in the common source line region.Type: ApplicationFiled: May 11, 2022Publication date: November 17, 2022Applicant: Applied Materials, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee
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Publication number: 20220319601Abstract: Described is a memory string including at least one select gate for drain (SGD) transistor and at least one memory transistor in a vertical hole extending through a memory stack on a substrate. The memory stack comprises alternating word lines and dielectric material. There is at least one select-gate-for-drain (SGD) transistor in a first vertical hole extending through the memory stack, the select-gate-for-drain (SGD) transistor comprising a first gate material. At least one memory transistor is in a second vertical hole extending through the memory stack, the at least one memory transistor comprising a second gate material different from the first gate material.Type: ApplicationFiled: March 28, 2022Publication date: October 6, 2022Applicant: Applied Materials, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee, Qian Fu, Sung-Kwan Kang, Takehito Koshizawa, Fredrick Fishburn
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Publication number: 20220285362Abstract: Methods for forming three-dimensional dynamic random-access memory (3D DRAM) structures that leverage a grid pattern of high aspect ratio holes to form subsequent features of the 3D DRAM. The method may include depositing alternating layers of crystalline silicon (c-Si) and crystalline silicon germanium (c-SiGe) using an heteroepitaxy process onto a substrate and HAR etching of a pattern of holes into the substrate. The holes configured to provide chemistry access to laterally etch or deposit materials to form 3D DRAM features without requiring subsequent HAR etching of holes to form the 3D DRAM features.Type: ApplicationFiled: February 17, 2022Publication date: September 8, 2022Inventors: Fredrick David FISHBURN, Arvind KUMAR, Sony VARGHESE, Chang Seok KANG, Sung-Kwan KANG, Tomohiko KITAJIMA
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Patent number: 11430801Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.Type: GrantFiled: April 12, 2021Date of Patent: August 30, 2022Assignee: APPLIED MATERIALS, INC.Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy
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Publication number: 20220262619Abstract: Methods of manufacturing memory devices are provided. The methods improve the quality of a selectively deposited silicon-containing dielectric layer. The method comprises selectively depositing a silicon-containing dielectric layer in a recessed region of a film stack. The selectively deposited silicon-containing dielectric layer is then exposed to a high-density plasma and annealed at a temperature greater than 800 ° C. to provide a silicon-containing dielectric film having a wet etch rate of less than 4 ?/min.Type: ApplicationFiled: February 9, 2022Publication date: August 18, 2022Applicant: Applied Materials, Inc.Inventors: Ning Li, Shuaidl Zhang, Mihaela A. Balseanu, Qi Gao, Rajesh Prasad, Tomohiko Kitajima, Chang Seok Kang, Deven Matthew Raj Mittal, Kyu-Ha Shim
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Publication number: 20220108728Abstract: Memory devices are described. The memory devices include a plurality of bit lines extending through a stack of alternating memory layers and dielectric layers. Each of the memory layers comprises a single crystalline-like silicon layer and includes a first word line, a second word line, a first capacitor, and a second capacitor. Methods of forming stacked memory devices are also described.Type: ApplicationFiled: December 15, 2021Publication date: April 7, 2022Applicant: Applied Materials, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee, Sanjay Natarajan, Sung-Kwan Kang, Lequn Liu
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Patent number: 11295786Abstract: Memory devices are described. The memory devices include a plurality of bit lines extending through a stack of alternating memory layers and dielectric layers. Each of the memory layers comprises a single crystalline-like silicon layer and includes a first word line, a second word line, a first capacitor, and a second capacitor. Methods of forming stacked memory devices are also described.Type: GrantFiled: February 3, 2020Date of Patent: April 5, 2022Assignee: Applied Materials, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee, Sanjay Natarajan, Sung-Kwan Kang, Lequn Liu
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Publication number: 20220059555Abstract: Described is a memory string including at least one select gate for drain (SGD) transistor and at least one memory transistor in a vertical hole extending through a memory stack on a substrate. The memory stack comprises alternating non-replacement word lines and replacement insulators. A filled slit extends through the memory stack, and there are at least two select gate for drain (SGD) isolation regions in the memory stack adjacent the filled slit. A select-gate-for-drain (SGD) cut is patterned into the top few pairs of alternating layers in the memory stacks. Through the cut opening, the sacrificial layer of the memory stacks is removed, and an insulator layer is used to fill the opening.Type: ApplicationFiled: August 11, 2021Publication date: February 24, 2022Applicant: Applied Material, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima
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Publication number: 20220005810Abstract: Described are memory devices having stacked DRAM cells, resulting in an increase in DRAM cell bit-density. The area of a unit cell is composed of a capacitor, a cell transistor, an isolation region and a connection region, where every capacitor and active region for the cell capacitor is electrically isolated. The memory cells have supporting bars. Methods of forming a memory device are described. The methods include patterning the isolation region with supporting bars, removing non-insulator layers after isolation region patterning, and filling the opened region with an insulator.Type: ApplicationFiled: June 22, 2021Publication date: January 6, 2022Applicant: Applied Materials, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima
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Publication number: 20210399011Abstract: Described is selective deposition of a silicon nitride (SiN) trap layer to form a memory device. A sacrificial layer is used for selective deposition in order to permit selective trap deposition. The trap layer is formed by deposition of a mold including a sacrificial layer, memory hole (MH) patterning, sacrificial layer recess from MH side, forming a deposition-enabling layer (DEL) on a side of the recess, and selective deposition of trap layer. After removing the sacrificial layer from a slit pattern opening, the deposition-enabling layer (DEL) is converted into an oxide to be used as blocking oxide.Type: ApplicationFiled: June 14, 2021Publication date: December 23, 2021Applicant: Applied Materials, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima, Mihaela A. Balseanu
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Patent number: 11189635Abstract: Methods of manufacturing memory devices are provided. The methods decrease the thickness of the first layers and increase the thickness of the second layers. Semiconductor devices are described having a film stack comprising alternating nitride and second layers in a first portion of the device, the alternating nitride and second layers of the film stack having a nitride:oxide thickness ratio (Nf:Of); and a memory stack comprising alternating word line and second layers in a second portion of the device, the alternating word line and second layers of the memory stack having a word line:oxide thickness ratio (Wm:Om), wherein 0.1(Wm:Om)<Nf:Of<0.95(Wm:Om).Type: GrantFiled: March 30, 2020Date of Patent: November 30, 2021Assignee: APPLIED MATERIALS, INC.Inventors: Chang Seok Kang, Tomohiko Kitajima, Mukund Srinivasan, Sanjay Natarajan
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Patent number: 11158650Abstract: Embodiments of the present disclosure provide an apparatus and methods for forming stair-like structures with accurate profiles and dimension control for manufacturing three dimensional (3D) stacked memory cell semiconductor devices. In one embodiment, a memory cell device includes a film stack comprising alternating pairs of dielectric layers and conductive structures horizontally formed on a substrate, and an opening formed in the film stack, wherein the opening is filled with a metal dielectric layer, a multi-layer structure and a center filling layer, wherein the metal dielectric layer in the opening is interfaced with the conductive structure.Type: GrantFiled: October 18, 2019Date of Patent: October 26, 2021Assignee: Applied Materials, Inc.Inventors: ChangSeok Kang, Tomohiko Kitajima
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Publication number: 20210257375Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.Type: ApplicationFiled: April 12, 2021Publication date: August 19, 2021Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy
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Publication number: 20210249415Abstract: Memory devices incorporating bridged word lines are described. The memory devices include a plurality of active regions spaced along a first direction, a second direction and a third direction. A plurality of conductive layers is arranged so that at least one conductive layer is adjacent to at least one side of each of the active regions along the third direction. A conductive bridge extends along the second direction to connect each of the conductive layers to one or more adjacent conductive layer. Some embodiments include an integrated etch stop layer. Methods of forming stacked memory devices are also described.Type: ApplicationFiled: January 27, 2021Publication date: August 12, 2021Applicant: Applied Materials, Inc.Inventors: CHANG SEOK KANG, Tomohiko Kitajima, Nitin K. Ingle, Sung-Kwan Kang
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Publication number: 20210233779Abstract: Memory devices and methods of manufacturing memory devices are provided. The device and methods described suppress oxidation of metal layers exposed to ambient oxygen. After an opening is formed, a nitridation process occurs to nitridate the surface of the exposed metal layer inside the opening. The nitridated region formed on the surface of metal layer inside the opening works as a barrier layer for oxygen diffusion. In addition, the nitridated region works as an electrode for charge trap memory cells.Type: ApplicationFiled: January 13, 2021Publication date: July 29, 2021Applicant: Applied Materials, Inc.Inventors: Chang Seok Kang, Tomohiko Kitajima, Sung-Kwan Kang
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Publication number: 20210233918Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.Type: ApplicationFiled: April 12, 2021Publication date: July 29, 2021Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy