Patents by Inventor Ramachandra Divakaruni

Ramachandra Divakaruni 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).

  • Publication number: 20180138095
    Abstract: A method for forming CMOS devices includes masking a first portion of a tensile-strained silicon layer of a SOI substrate, doping a second portion of the layer outside the first portion and growing an undoped silicon layer on the doped portion and the first portion. The undoped silicon layer becomes tensile-strained. Strain in the undoped silicon layer over the doped portion is relaxed by converting the doped portion to a porous silicon to form a relaxed silicon layer. The porous silicon is converted to an oxide. A SiGe layer is grown and oxidized to convert the relaxed silicon layer to a compressed SiGe layer. Fins are etched in the first portion from the tensile-strained silicon layer and the undoped silicon layer and in the second portion from the compressed SiGe layer.
    Type: Application
    Filed: December 21, 2017
    Publication date: May 17, 2018
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim, Juntao Li, Devendra K. Sadana
  • Patent number: 9966253
    Abstract: A nanotip apparatus which includes nanotips arranged in a pattern on a semiconductor base. Each of the nanotips have a pointed tip portion and a base portion in contact with the semiconductor base. Further, each of the nanotips include a gradient of silicon germanium (SiGe) with the highest concentration of germanium being at the pointed tip portion and the lowest concentration of germanium being at the base in contact with the semiconductor base. Also disclosed is a method in which the nanotips may be formed.
    Type: Grant
    Filed: February 25, 2016
    Date of Patent: May 8, 2018
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li, Shogo Mochizuki
  • Publication number: 20180122712
    Abstract: A method for forming CMOS devices includes masking a first portion of a tensile-strained silicon layer of a SOI substrate, doping a second portion of the layer outside the first portion and growing an undoped silicon layer on the doped portion and the first portion. The undoped silicon layer becomes tensile-strained. Strain in the undoped silicon layer over the doped portion is relaxed by converting the doped portion to a porous silicon to form a relaxed silicon layer. The porous silicon is converted to an oxide. A SiGe layer is grown and oxidized to convert the relaxed silicon layer to a compressed SiGe layer. Fins are etched in the first portion from the tensile-strained silicon layer and the undoped silicon layer and in the second portion from the compressed SiGe layer.
    Type: Application
    Filed: December 19, 2017
    Publication date: May 3, 2018
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim, Juntao Li, Devendra K. Sadana
  • Patent number: 9960168
    Abstract: Structures and methods for deep trench capacitor connections are disclosed. The structure includes a reduced diameter top portion of the capacitor conductor. This increases the effective spacing between neighboring deep trench capacitors. Silicide or additional polysilicon are then deposited to complete the connection between the deep trench capacitor and a neighboring transistor.
    Type: Grant
    Filed: December 24, 2014
    Date of Patent: May 1, 2018
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Veeraraghavan S. Basker, Kangguo Cheng, Benjamin Ryan Cipriany, Ramachandra Divakaruni, Brian J. Greene, Ali Khakifirooz, Byeong Yeol Kim, William Larsen Nicoll
  • Publication number: 20180114865
    Abstract: A method for forming a semiconductor device includes etching a semiconductor layer using a gate structure and spacers as a mask to protect portions of the semiconductor layer that extend beyond the gate structure. Undercuts are formed in a buried dielectric layer under the gate structure. Source and drain regions are epitaxially growing and wrapped around the semiconductor layer by forming the source and drain regions adjacent to the gate structure on a first side of the semiconductor layer and in the undercuts on a second side of the semiconductor layer opposite the first side.
    Type: Application
    Filed: December 13, 2017
    Publication date: April 26, 2018
    Inventors: Kangguo Cheng, Ramachandra Divakaruni
  • Patent number: 9954109
    Abstract: A vertical transistor includes a gate structure interposed between a proximate spacer doped with a first dopant-type and a distal spacer doped with the first dopant-type. The proximate spacer is formed on an upper surface of a semiconductor substrate. At least one channel region extends vertically from the proximate doping source layer to the distal doping source layer. A proximate S/D extension region is adjacent the proximate spacer and a distal S/D extension region is adjacent the distal spacer. The proximate and distal S/D extension regions include dopants that match the first dopant-type of the proximate and distal doping sources.
    Type: Grant
    Filed: May 5, 2016
    Date of Patent: April 24, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Ramachandra Divakaruni
  • Publication number: 20180108751
    Abstract: Transistors include stress liners, with one or more semiconductor structures between the stress liners. The stress liners provide a stress on the one or more semiconductor structures. A gate is formed over and around the one or more semiconductor structures. A source and drain region is formed on the one or more semiconductor structures on opposite sides of the gate, between the stress liners.
    Type: Application
    Filed: December 8, 2017
    Publication date: April 19, 2018
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li, Xin Miao
  • Publication number: 20180097076
    Abstract: A method is presented for forming a semiconductor structure. The method includes forming a bilayer buried insulator over a substrate, forming an extremely thin silicon-on-insulator (ETSOI) over the bilayer buried insulator, forming a dummy gate, and forming a source/drain next to the dummy gate, the source/drain defining a raised source/drain region. The method further includes depositing a dielectric material over the raised source/drain regions, removing the dummy gate to define a recess, implanting a species within a first layer of the bilayer buried insulator, and depositing a gate dielectric and a conducting material within the recess. The method further includes removing the substrate, etching the implanted portion of the first layer of the bilayer buried insulator to expose a surface of a second layer of the bilayer buried insulator, and forming a back gate over the exposed second layer, the back gate self-aligned to the ETSOI channel.
    Type: Application
    Filed: September 30, 2016
    Publication date: April 5, 2018
    Inventors: Kangguo Cheng, Ramachandra Divakaruni
  • Patent number: 9929060
    Abstract: A method for forming CMOS devices includes masking a first portion of a tensile-strained silicon layer of a SOI substrate, doping a second portion of the layer outside the first portion and growing an undoped silicon layer on the doped portion and the first portion. The undoped silicon layer becomes tensile-strained. Strain in the undoped silicon layer over the doped portion is relaxed by converting the doped portion to a porous silicon to form a relaxed silicon layer. The porous silicon is converted to an oxide. A SiGe layer is grown and oxidized to convert the relaxed silicon layer to a compressed SiGe layer. Fins are etched in the first portion from the tensile-strained silicon layer and the undoped silicon layer and in the second portion from the compressed SiGe layer.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: March 27, 2018
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim, Juntao Li, Devendra K. Sadana
  • Patent number: 9917199
    Abstract: A method for forming a semiconductor device includes etching a semiconductor layer using a gate structure and spacers as a mask to protect portions of the semiconductor layer that extend beyond the gate structure. Undercuts are formed in a buried dielectric layer under the gate structure. Source and drain regions are epitaxially growing and wrapped around the semiconductor layer by forming the source and drain regions adjacent to the gate structure on a first side of the semiconductor layer and in the undercuts on a second side of the semiconductor layer opposite the first side.
    Type: Grant
    Filed: February 22, 2017
    Date of Patent: March 13, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Ramachandra Divakaruni
  • Patent number: 9917021
    Abstract: A method for forming CMOS devices includes masking a first portion of a tensile-strained silicon layer of a SOI substrate, doping a second portion of the layer outside the first portion and growing an undoped silicon layer on the doped portion and the first portion. The undoped silicon layer becomes tensile-strained. Strain in the undoped silicon layer over the doped portion is relaxed by converting the doped portion to a porous silicon to form a relaxed silicon layer. The porous silicon is converted to an oxide. A SiGe layer is grown and oxidized to convert the relaxed silicon layer to a compressed SiGe layer. Fins are etched in the first portion from the tensile-strained silicon layer and the undoped silicon layer and in the second portion from the compressed SiGe layer.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: March 13, 2018
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim, Juntao Li, Devendra K. Sadana
  • Patent number: 9911834
    Abstract: Transistors include multiple stress liners. One or more channel structures are suspended at opposite ends from the plurality of stress liners. The stress liners provide a stress on the one or more channel structures. A gate is formed over and around the one or more channel structures, defining a channel region of the one or more channel structures that is covered by the gate. A source and drain region are formed on opposite sides of the gate.
    Type: Grant
    Filed: November 21, 2016
    Date of Patent: March 6, 2018
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li, Xin Miao
  • Patent number: 9865509
    Abstract: A method for forming a complementary metal oxide semiconductor (CMOS) device includes growing a SiGe layer on a Si semiconductor layer, and etching fins through the SiGe layer and the Si semiconductor layer down to a buried dielectric layer. Spacers are formed on sidewalls of the fins, and a dielectric material is formed on top of the buried dielectric layer between the fins. The SiGe layer is replaced with a dielectric cap for an n-type device to form a Si fin. The Si semiconductor layer is converted to a SiGe fin for a p-type device by oxidizing the SiGe layer to condense Ge. The dielectric material is recessed to below the spacers, and the dielectric cap and the spacers are removed to expose the Si fin and the SiGe fin.
    Type: Grant
    Filed: August 17, 2016
    Date of Patent: January 9, 2018
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim
  • Publication number: 20170323952
    Abstract: Transistors include multiple stress liners. One or more channel structures are suspended at opposite ends from the plurality of stress liners. The stress liners provide a stress on the one or more channel structures. A gate is formed over and around the one or more channel structures, defining a channel region of the one or more channel structures that is covered by the gate. A source and drain region are formed on opposite sides of the gate.
    Type: Application
    Filed: November 21, 2016
    Publication date: November 9, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao LI, Xin Miao
  • Publication number: 20170323953
    Abstract: Transistors and methods of forming the same include forming a fin of alternating layers of a channel material and a sacrificial material. Stress liners are formed in contact with both ends of the fin. The stress liners exert a stress on the fin. The sacrificial material is etched away from the fin, such that the layers of the channel material are suspended between the stress liners. A gate stack is formed over and around the suspended layers of channel material.
    Type: Application
    Filed: March 31, 2017
    Publication date: November 9, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao LI, Xin Miao
  • Publication number: 20170323977
    Abstract: A vertical transistor includes a gate structure interposed between a proximate spacer doped with a first dopant-type and a distal spacer doped with the first dopant-type. The proximate spacer is formed on an upper surface of a semiconductor substrate. At least one channel region extends vertically from the proximate doping source layer to the distal doping source layer. A proximate S/D extension region is adjacent the proximate spacer and a distal S/D extension region is adjacent the distal spacer. The proximate and distal S/D extension regions include dopants that match the first dopant-type of the proximate and distal doping sources.
    Type: Application
    Filed: May 5, 2016
    Publication date: November 9, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni
  • Publication number: 20170294358
    Abstract: A semiconductor device comprises first stack of nanowires arranged on a substrate comprises a first nanowire and a second nanowire, the second nanowire is arranged substantially co-planar in a first plane with the first nanowire the first nanowire and the second nanowire arranged substantially parallel with the substrate, a second stack of nanowires comprises a third nanowire and a fourth nanowire, the third nanowire and the fourth nanowire arranged substantially co-planar in the first plane with the first nanowire, and the first nanowire and the second nanowire comprises a first semiconductor material and the third nanowire and the fourth nanowire comprises a second semiconductor material, the first semiconductor material dissimilar from the second semiconductor material.
    Type: Application
    Filed: June 21, 2017
    Publication date: October 12, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li
  • Publication number: 20170271525
    Abstract: A method for forming a semiconductor device includes etching a semiconductor layer using a gate structure and spacers as a mask to protect portions of the semiconductor layer that extend beyond the gate structure. Undercuts are formed in a buried dielectric layer under the gate structure. Source and drain regions are epitaxially growing and wrapped around the semiconductor layer by forming the source and drain regions adjacent to the gate structure on a first side of the semiconductor layer and in the undercuts on a second side of the semiconductor layer opposite the first side.
    Type: Application
    Filed: February 22, 2017
    Publication date: September 21, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni
  • Publication number: 20170250248
    Abstract: A nanotip apparatus which includes nanotips arranged in a pattern on a semiconductor base. Each of the nanotips have a pointed tip portion and a base portion in contact with the semiconductor base. Further, each of the nanotips include a gradient of silicon germanium (SiGe) with the highest concentration of germanium being at the pointed tip portion and the lowest concentration of germanium being at the base in contact with the semiconductor base. Also disclosed is a method in which the nanotips may be formed.
    Type: Application
    Filed: February 25, 2016
    Publication date: August 31, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li, Shogo Mochizuki
  • Patent number: 9735269
    Abstract: Transistors and methods of forming the same include forming a fin of alternating layers of a channel material and a sacrificial material. Stress liners are formed in contact with both ends of the fin. The stress liners exert a stress on the fin. The sacrificial material is etched away from the fin, such that the layers of the channel material are suspended between the stress liners. A gate stack is formed over and around the suspended layers of channel material.
    Type: Grant
    Filed: May 6, 2016
    Date of Patent: August 15, 2017
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li, Xin Miao