Patents by Inventor Senaka Krishna Kanakamedala
Senaka Krishna Kanakamedala 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: 11437270Abstract: A method of forming a memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate forming memory stack structures through the alternating stack, forming a first backside trench and a second backside trench through the alternating stack, forming backside recesses by removing the sacrificial material layers, depositing a backside blocking dielectric layer after formation of the backside recesses, forming a liner that a lesser lateral extent than a lateral distance between the first backside trench and the second backside trench; and selectively growing a metal from surfaces of the liners while either not growing or growing at a lower rate the metal from surfaces of the backside recesses that are not covered by the liners.Type: GrantFiled: November 19, 2019Date of Patent: September 6, 2022Assignee: SANDISK TECHNOLOGIES LLCInventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar, Senaka Krishna Kanakamedala, Fumitaka Amano, Genta Mizuno
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Patent number: 10950629Abstract: A three-dimensional memory device includes alternating stacks of insulating strips and electrically conductive strips laterally spaced apart by line trenches, and an alternating two-dimensional array of memory stack assemblies and dielectric pillar structures located in the line trenches. Each of the line trenches is filled with a respective laterally alternating sequence of memory stack assemblies and dielectric pillar structures. Each memory stack assembly includes a vertical semiconductor channel and a pair of memory film. The vertical semiconductor channel includes a semiconductor channel layer having large grains, which can be provided by a selective semiconductor growth from seed semiconductor material layers, sacrificial semiconductor material layers, or a single crystalline semiconductor material in a semiconductor substrate underlying the alternating stacks.Type: GrantFiled: May 19, 2020Date of Patent: March 16, 2021Assignee: SANDISK TECHNOLOGIES LLCInventors: Raghuveer S. Makala, Fei Zhou, Senaka Krishna Kanakamedala, Yao-Sheng Lee
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Publication number: 20200279868Abstract: A three-dimensional memory device includes alternating stacks of insulating strips and electrically conductive strips laterally spaced apart by line trenches, and an alternating two-dimensional array of memory stack assemblies and dielectric pillar structures located in the line trenches. Each of the line trenches is filled with a respective laterally alternating sequence of memory stack assemblies and dielectric pillar structures. Each memory stack assembly includes a vertical semiconductor channel and a pair of memory film. The vertical semiconductor channel includes a semiconductor channel layer having large grains, which can be provided by a selective semiconductor growth from seed semiconductor material layers, sacrificial semiconductor material layers, or a single crystalline semiconductor material in a semiconductor substrate underlying the alternating stacks.Type: ApplicationFiled: May 19, 2020Publication date: September 3, 2020Inventors: Raghuveer S. Makala, Fei Zhou, Senaka Krishna Kanakamedala, Yao-Sheng Lee
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Patent number: 10700086Abstract: A three-dimensional memory device includes alternating stacks of insulating strips and electrically conductive strips laterally spaced apart by line trenches, and an alternating two-dimensional array of memory stack assemblies and dielectric pillar structures located in the line trenches. Each of the line trenches is filled with a respective laterally alternating sequence of memory stack assemblies and dielectric pillar structures. Each memory stack assembly includes a vertical semiconductor channel and a pair of memory film. The vertical semiconductor channel includes a semiconductor channel layer having large grains, which can be provided by a selective semiconductor growth from seed semiconductor material layers, sacrificial semiconductor material layers, or a single crystalline semiconductor material in a semiconductor substrate underlying the alternating stacks.Type: GrantFiled: June 28, 2018Date of Patent: June 30, 2020Assignee: SANDISK TECHNOLOGIES LLCInventors: Raghuveer S. Makala, Fei Zhou, Senaka Krishna Kanakamedala, Yao-Sheng Lee
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Publication number: 20200105595Abstract: A method of forming a memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate forming memory stack structures through the alternating stack, forming a first backside trench and a second backside trench through the alternating stack, forming backside recesses by removing the sacrificial material layers, depositing a backside blocking dielectric layer after formation of the backside recesses, forming a liner that a lesser lateral extent than a lateral distance between the first backside trench and the second backside trench; and selectively growing a metal from surfaces of the liners while either not growing or growing at a lower rate the metal from surfaces of the backside recesses that are not covered by the liners.Type: ApplicationFiled: November 19, 2019Publication date: April 2, 2020Inventors: Rahul SHARANGPANI, Raghuveer S. MAKALA, Fei ZHOU, Adarsh RAJASHEKHAR, Senaka Krishna KANAKAMEDALA, Fumitaka AMANO, Genta MIZUNO
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Patent number: 10529620Abstract: A method of forming a memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate forming memory stack structures through the alternating stack, forming a first backside trench and a second backside trench through the alternating stack, forming backside recesses by removing the sacrificial material layers, depositing a backside blocking dielectric layer after formation of the backside recesses, forming a liner that a lesser lateral extent than a lateral distance between the first backside trench and the second backside trench; and selectively growing a metal from surfaces of the liners while either not growing or growing at a lower rate the metal from surfaces of the backside recesses that are not covered by the liners.Type: GrantFiled: December 4, 2017Date of Patent: January 7, 2020Assignee: SANDISK TECHNOLOGIES LLCInventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar, Senaka Krishna Kanakamedala, Fumitaka Amano, Genta Mizuno
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Publication number: 20200006376Abstract: A three-dimensional memory device includes alternating stacks of insulating strips and electrically conductive strips laterally spaced apart by line trenches, and an alternating two-dimensional array of memory stack assemblies and dielectric pillar structures located in the line trenches. Each of the line trenches is filled with a respective laterally alternating sequence of memory stack assemblies and dielectric pillar structures. Each memory stack assembly includes a vertical semiconductor channel and a pair of memory film. The vertical semiconductor channel includes a semiconductor channel layer having large grains, which can be provided by a selective semiconductor growth from seed semiconductor material layers, sacrificial semiconductor material layers, or a single crystalline semiconductor material in a semiconductor substrate underlying the alternating stacks.Type: ApplicationFiled: June 28, 2018Publication date: January 2, 2020Inventors: Raghuveer S. Makala, Fei Zhou, Senaka Krishna Kanakamedala, Yao-Sheng Lee
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Patent number: 10461163Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate. Memory stack structures are located in a memory array region, each of which includes a memory film and a vertical semiconductor channel. Contact via structures located in the terrace region and contact a respective one of the electrically conductive layers. Each of the electrically conductive layers has a respective first thickness throughout the memory array region and includes a contact portion having a respective second thickness that is greater than the respective first thickness within a terrace region. The greater thickness of the contact portion prevents an etch-through during formation of contact via cavities for forming the contact via structures.Type: GrantFiled: November 15, 2017Date of Patent: October 29, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Senaka Krishna Kanakamedala, Yoshihiro Kanno, Raghuveer S. Makala, Yanli Zhang, Jin Liu, Murshed Chowdhury, Yao-Sheng Lee
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Patent number: 10453854Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate. Memory stack structures are located in a memory array region, each of which includes a memory film and a vertical semiconductor channel. Contact via structures located in the terrace region and contact a respective one of the electrically conductive layers. Each of the electrically conductive layers has a respective first thickness throughout the memory array region and includes a contact portion having a respective second thickness that is greater than the respective first thickness within a terrace region. The greater thickness of the contact portion prevents an etch-through during formation of contact via cavities for forming the contact via structures.Type: GrantFiled: November 15, 2017Date of Patent: October 22, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Yoshihiro Kanno, Senaka Krishna Kanakamedala, Raghuveer S. Makala, Yanli Zhang, Jin Liu, Murshed Chowdhury
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Patent number: 10438964Abstract: A strap level sacrificial layer and an alternating stack of insulating layers and spacer material layers are formed over a substrate. An array of memory stack structures is formed through the alternating stack and the strap level sacrificial layer. Each memory film in the memory stack structures includes a metal oxide blocking dielectric. After formation of a source cavity by removal of the strap level sacrificial layer, an atomic layer etch process can be employed to remove portions of the metal oxide blocking dielectrics at the level of the source cavity. Outer sidewalls of semiconductor channels in the memory stack structures are exposed by additional etch processes, and a source strap layer is selectively deposited in the source cavity in contact with the semiconductor channel. If the spacer material layers are sacrificial material layers, all volumes of the sacrificial material layers can be replaced with the electrically conductive layers.Type: GrantFiled: June 26, 2017Date of Patent: October 8, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Raghuveer S. Makala, Senaka Krishna Kanakamedala, Yanli Zhang, Yao-Sheng Lee
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Patent number: 10381364Abstract: A three-dimensional memory device can be formed by first forming an alternating stack of insulating layers and stack level spacer material layers over a substrate. The stack level spacer material layers can be formed as, or are subsequently replaced with, stack level electrically conductive layers. A bottommost insulating spacer layer is formed with recesses that form grooves that are laterally spaced apart. Drain select level electrically conductive layers are formed over protruding portions and within the grooves of the bottommost insulating spacer layer by anisotropic deposition and isotropic etch back of a conductive material. Additional insulating spacer layers may be formed by anisotropic deposition of an insulating material. Additional drain select level electrically conductive layers can be formed by anisotropic deposition and isotropic etch back of additional conductive material.Type: GrantFiled: June 20, 2017Date of Patent: August 13, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Fei Zhou, Rahul Sharangpani, Yanli Zhang, Raghuveer S. Makala, Senaka Krishna Kanakamedala
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Publication number: 20190148392Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate. Memory stack structures are located in a memory array region, each of which includes a memory film and a vertical semiconductor channel. Contact via structures located in the terrace region and contact a respective one of the electrically conductive layers. Each of the electrically conductive layers has a respective first thickness throughout the memory array region and includes a contact portion having a respective second thickness that is greater than the respective first thickness within a terrace region. The greater thickness of the contact portion prevents an etch-through during formation of contact via cavities for forming the contact via structures.Type: ApplicationFiled: November 15, 2017Publication date: May 16, 2019Inventors: Yoshihiro KANNO, Senaka Krishna KANAKAMEDALA, Raghuveer S. MAKALA, Yanli ZHANG, Jin LIU, Murshed CHOWDHURY
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Publication number: 20190148506Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate. Memory stack structures are located in a memory array region, each of which includes a memory film and a vertical semiconductor channel. Contact via structures located in the terrace region and contact a respective one of the electrically conductive layers. Each of the electrically conductive layers has a respective first thickness throughout the memory array region and includes a contact portion having a respective second thickness that is greater than the respective first thickness within a terrace region. The greater thickness of the contact portion prevents an etch-through during formation of contact via cavities for forming the contact via structures.Type: ApplicationFiled: November 15, 2017Publication date: May 16, 2019Inventors: Senaka Krishna KANAKAMEDALA, Yoshihiro KANNO, Raghuveer S. MAKALA, Yanli ZHANG, Jin LIU, Murshed CHOWDHURY, Yao-Sheng LEE
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Patent number: 10199434Abstract: A phase change memory device includes a vertical stack of multiple two-dimensional arrays of pillar structures. Each of the multiple two-dimensional arrays of pillar structures is located within a respective array level. Each two-dimensional array among the multiple two-dimensional arrays of pillar structures is contacted by a respective overlying one-dimensional array of conductive rails laterally extending along a first horizontal direction and a respective underlying one-dimensional array of conductive rails laterally extending along a second horizontal direction different from the first direction. Each pillar structure within the multiple two-dimensional arrays of pillar structures includes a phase change memory element and a selector element in a series connection with the phase change memory element. A first set of dielectric isolation structures having a first homogeneous composition vertically extends continuously through two vertically neighboring array levels.Type: GrantFiled: February 5, 2018Date of Patent: February 5, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Yao-Sheng Lee, Senaka Krishna Kanakamedala, Raghuveer S. Makala
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Publication number: 20180374866Abstract: A strap level sacrificial layer and an alternating stack of insulating layers and spacer material layers are formed over a substrate. An array of memory stack structures is formed through the alternating stack and the strap level sacrificial layer. Each memory film in the memory stack structures includes a metal oxide blocking dielectric. After formation of a source cavity by removal of the strap level sacrificial layer, an atomic layer etch process can be employed to remove portions of the metal oxide blocking dielectrics at the level of the source cavity. Outer sidewalls of semiconductor channels in the memory stack structures are exposed by additional etch processes, and a source strap layer is selectively deposited in the source cavity in contact with the semiconductor channel. If the spacer material layers are sacrificial material layers, all volumes of the sacrificial material layers can be replaced with the electrically conductive layers.Type: ApplicationFiled: June 26, 2017Publication date: December 27, 2018Inventors: Raghuveer S. MAKALA, Senaka Krishna KANAKAMEDALA, Yanli ZHANG, Yao-Sheng LEE
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Publication number: 20180366482Abstract: A three-dimensional memory device can be formed by first forming an alternating stack of insulating layers and stack level spacer material layers over a substrate. The stack level spacer material layers can be formed as, or are subsequently replaced with, stack level electrically conductive layers. A bottommost insulating spacer layer is formed with recesses that form grooves that are laterally spaced apart. Drain select level electrically conductive layers are formed over protruding portions and within the grooves of the bottommost insulating spacer layer by anisotropic deposition and isotropic etch back of a conductive material. Additional insulating spacer layers may be formed by anisotropic deposition of an insulating material. Additional drain select level electrically conductive layers can be formed by anisotropic deposition and isotropic etch back of additional conductive material.Type: ApplicationFiled: June 20, 2017Publication date: December 20, 2018Inventors: Fei Zhou, Rahul Sharangpani, Yanli Zhang, Raghuveer S. Makala, Senaka Krishna Kanakamedala
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Patent number: 10128261Abstract: A memory film and a semiconductor channel can be formed within each memory opening that extends through a stack including an alternating plurality of insulator layers and sacrificial material layers. After formation of backside recesses through removal of the sacrificial material layers selective to the insulator layers, a metallic barrier material portion can be formed in each backside recess. A cobalt portion can be formed in each backside recess. Each backside recess can be filled with a cobalt portion alone, or can be filled with a combination of a cobalt portion and a metallic material portion including a material other than cobalt.Type: GrantFiled: February 4, 2015Date of Patent: November 13, 2018Assignee: SANDISK TECHNOLOGIES LLCInventors: Raghuveer S. Makala, Rahul Sharangpani, Sateesh Koka, Genta Mizuno, Naoki Takeguchi, Senaka Krishna Kanakamedala, George Matamis, Yao-Sheng Lee, Johann Alsmeier
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Publication number: 20180090373Abstract: A method of forming a memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate forming memory stack structures through the alternating stack, forming a first backside trench and a second backside trench through the alternating stack, forming backside recesses by removing the sacrificial material layers, depositing a backside blocking dielectric layer after formation of the backside recesses, forming a liner that a lesser lateral extent than a lateral distance between the first backside trench and the second backside trench; and selectively growing a metal from surfaces of the liners while either not growing or growing at a lower rate the metal from surfaces of the backside recesses that are not covered by the liners.Type: ApplicationFiled: December 4, 2017Publication date: March 29, 2018Inventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar, Senaka Krishna Kanakamedala, Fumitaka Amano, Genta Mizuno
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Publication number: 20170287925Abstract: A memory film and a semiconductor channel can be formed within each memory opening that extends through a stack including an alternating plurality of insulator layers and sacrificial material layers. After formation of backside recesses through removal of the sacrificial material layers selective to the insulator layers, a metallic barrier material portion can be formed in each backside recess. A cobalt portion can be formed in each backside recess. Each backside recess can be filled with a cobalt portion alone, or can be filled with a combination of a cobalt portion and a metallic material portion including a material other than cobalt.Type: ApplicationFiled: February 4, 2015Publication date: October 5, 2017Inventors: Raghuveer S. MAKALA, Rahul SHARANGPANI, Sateesh KOKA, Genta MIZUNO, Naoki TAKEGUCHI, Senaka Krishna KANAKAMEDALA, George MATAMIS, Yao-Sheng LEE, Johann ALSMEIER
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Patent number: 9691884Abstract: Methods of making a monolithic three dimensional NAND string that include forming a stack of alternating first material layers and second material layers over a substrate, where each of the second material layers includes a layer of a first silicon oxide material between two layers of a second silicon oxide material different from the first silicon oxide material, etching the stack to form a front side opening in the stack, forming a memory film over a sidewall of the front side opening, and forming a semiconductor channel in the front side opening such that at least a portion of the memory film is located between the semiconductor channel and the sidewall of the front side opening, where at least one of an air gap or a material which has a dielectric constant below 3.9 is formed between the respective two layers of second silicon oxide material.Type: GrantFiled: August 26, 2014Date of Patent: June 27, 2017Assignee: SANDISK TECHNOLOGIES LLCInventors: Raghuveer S. Makala, Yanli Zhang, Rahul Sharangpani, Yao-Sheng Lee, Senaka Krishna Kanakamedala, George Matamis, Johann Alsmeier