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).

  • Patent number: 9735173
    Abstract: A semiconductor device includes a buried dielectric layer and a semiconductor layer provided on the buried dielectric layer. A gate structure is formed on the semiconductor layer and has portions of the semiconductor layer extending beyond the gate structure. Source and drain regions are wrapped around ends of the semiconductor layer such that a first portion of the source and drain regions is formed on a first side of the semiconductor layer adjacent to the gate structure, and a second portion of the source and drain regions is formed on a second side of the semiconductor layer opposite the first side.
    Type: Grant
    Filed: March 17, 2016
    Date of Patent: August 15, 2017
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni
  • Patent number: 9735277
    Abstract: One embodiment provides a method comprising etching a fin of a fin-shaped field effect transistor (FinFET) to form a reduced fin, and laterally etching the reduced fin to form a fin channel including a first fin channel sidewall and a second fin channel sidewall opposing the first fin channel sidewall. The method further comprises forming a first thin dielectric tunnel and a second thin dielectric tunnel on the first fin channel sidewall and the second fin channel sidewall, respectively. Each thin dielectric tunnel prevents lateral epitaxial crystal growth on the fin channel. The method further comprises etching an insulator layer disposed between the fin channel and a substrate of the FinFET to expose portions of a substrate surface of the substrate. A source epitaxy and a drain epitaxy are formed from vertical epitaxial crystal growth on the exposed portions of the substrate surface after epitaxial deposition.
    Type: Grant
    Filed: October 27, 2016
    Date of Patent: August 15, 2017
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Johnathan E. Faltermeier, Edward J. Nowak, Kern Rim
  • Patent number: 9735234
    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: Grant
    Filed: July 12, 2016
    Date of Patent: August 15, 2017
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li
  • Publication number: 20170229458
    Abstract: A third type of metal gate stack is provided above an isolation structure and between a replacement metal gate n-type field effect transistor and a replacement metal gate p-type field effect transistor. The third type of metal gate stack includes at least three different components. Notably, the third type of metal gate stack includes, as a first component, an n-type workfunction metal layer, as a second component, a p-type workfunction metal layer, and as a third component, a low resistance metal layer. In some embodiments, the uppermost surface of the first, second and third components of the third type of metal gate stack are all substantially coplanar with each other. In other embodiments, an uppermost surface of the third component of the third type of metal gate stack is non-substantially coplanar with an uppermost surface of both the first and second components of the third type of metal gate stack.
    Type: Application
    Filed: April 24, 2017
    Publication date: August 10, 2017
    Applicant: International Business Machines Corporation
    Inventors: Ramachandra Divakaruni, Sameer H. Jain, Viraj Y. Sardesai, Keith H. Tabakman
  • Publication number: 20170229538
    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: July 12, 2016
    Publication date: August 10, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li
  • Publication number: 20170194435
    Abstract: A semiconductor structure includes a material stack located on a surface of a semiconductor substrate. The material stack includes, from bottom to top, a silicon germanium alloy portion that is substantially relaxed and defect-free and a semiconductor material pillar that is defect-free. A dielectric material structure surrounds sidewalls of the material stack and is present on exposed portions of the semiconductor substrate.
    Type: Application
    Filed: March 23, 2017
    Publication date: July 6, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Hong He, Juntao Li
  • Publication number: 20170170180
    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: Application
    Filed: June 20, 2016
    Publication date: June 15, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim
  • Publication number: 20170170076
    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: Application
    Filed: August 17, 2016
    Publication date: June 15, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim
  • Publication number: 20170170323
    Abstract: One embodiment provides a method comprising etching a fin of a fin-shaped field effect transistor (FinFET) to form a reduced fin, and laterally etching the reduced fin to form a fin channel including a first fin channel sidewall and a second fin channel sidewall opposing the first fin channel sidewall. The method further comprises forming a first thin dielectric tunnel and a second thin dielectric tunnel on the first fin channel sidewall and the second fin channel sidewall, respectively. Each thin dielectric tunnel prevents lateral epitaxial crystal growth on the fin channel. The method further comprises etching an insulator layer disposed between the fin channel and a substrate of the FinFET to expose portions of a substrate surface of the substrate. A source epitaxy and a drain epitaxy are formed from vertical epitaxial crystal growth on the exposed portions of the substrate surface after epitaxial deposition.
    Type: Application
    Filed: October 27, 2016
    Publication date: June 15, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Johnathan E. Faltermeier, Edward J. Nowak, Kern Rim
  • Publication number: 20170154982
    Abstract: A semiconductor device is provided that includes a pedestal of an insulating material present over at least one layer of a semiconductor material, and at least one fin structure in contact with the pedestal of the insulating material. Source and drain region structures are present on opposing sides of the at least one fin structure. At least one of the source and drain region structures includes at least two epitaxial material layers. A first epitaxial material layer is in contact with the at least one layer of semiconductor material. A second epitaxial material layer is in contact with the at least one fin structure. The first epitaxial material layer is separated from the at least one fin structure by the second epitaxial material layer. A gate structure present on the at least one fin structure.
    Type: Application
    Filed: February 14, 2017
    Publication date: June 1, 2017
    Inventors: KANGGUO CHENG, RAMACHANDRA DIVAKARUNI, ALI KHAKIFIROOZ, ALEXANDER REZNICEK, SOON-CHEON SEO
  • Patent number: 9660105
    Abstract: A flash memory device in a dual fin single floating gate configuration is provided. Semiconductor fins are formed on a stack of a back gate conductor layer and a back gate dielectric layer. Pairs of semiconductor fins are formed in an array environment such that shallow trench isolation structures can be formed along the lengthwise direction of the semiconductor fins within the array. After formation of tunneling dielectrics on the sidewalls of the semiconductor fins, a floating gate electrode is formed between each pair of proximally located semiconductor fins by deposition of a conformal conductive material layer and an isotropic etch. A control gate dielectric and a control gate electrode are formed by deposition and patterning of a dielectric layer and a conductive material layer.
    Type: Grant
    Filed: April 4, 2016
    Date of Patent: May 23, 2017
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: Ramachandra Divakaruni, Arvind Kumar, Carl J. Radens
  • Patent number: 9634006
    Abstract: A third type of metal gate stack is provided above an isolation structure and between a replacement metal gate n-type field effect transistor and a replacement metal gate p-type field effect transistor. The third type of metal gate stack includes at least three different components. Notably, the third type of metal gate stack includes, as a first component, an n-type workfunction metal layer, as a second component, a p-type workfunction metal layer, and as a third component, a low resistance metal layer. In some embodiments, the uppermost surface of the first, second and third components of the third type of metal gate stack are all substantially coplanar with each other. In other embodiments, an uppermost surface of the third component of the third type of metal gate stack is non-substantially coplanar with an uppermost surface of both the first and second components of the third type of metal gate stack.
    Type: Grant
    Filed: February 28, 2014
    Date of Patent: April 25, 2017
    Assignee: International Business Machines Corporation
    Inventors: Ramachandra Divakaruni, Sameer H. Jain, Viraj Y. Sardesai, Keith H. Tabakman
  • Patent number: 9620641
    Abstract: A semiconductor device is provided that includes a pedestal of an insulating material present over at least one layer of a semiconductor material, and at least one fin structure in contact with the pedestal of the insulating material. Source and drain region structures are present on opposing sides of the at least one fin structure. At least one of the source and drain region structures includes at least two epitaxial material layers. A first epitaxial material layer is in contact with the at least one layer of semiconductor material. A second epitaxial material layer is in contact with the at least one fin structure. The first epitaxial material layer is separated from the at least one fin structure by the second epitaxial material layer. A gate structure present on the at least one fin structure.
    Type: Grant
    Filed: February 22, 2016
    Date of Patent: April 11, 2017
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Ali Khakifirooz, Alexander Reznicek, Soon-Cheon Seo
  • Patent number: 9614077
    Abstract: A vertical transistor including a strained vertical semiconductor material channel pillar and a method of forming the same are provided. A strained vertical semiconductor materials pillar is first formed and is used to provide the strained vertical semiconductor material channel pillar of the vertical transistor of the present application. The strained vertical semiconductor material pillar is always mechanically anchored during various vertical transistor processing steps so that in the final structure strain is preserved.
    Type: Grant
    Filed: March 3, 2016
    Date of Patent: April 4, 2017
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Juntao Li
  • Patent number: 9613956
    Abstract: A technique relates to punchthrough stop (PTS) doping in bulk fin field effect transistors. Fins are formed on a substrate, and each pair of the fins has a fin pitch. Each of the fins has an undoped fin channel and a punchthrough stop doping region underneath the undoped fin channel. A narrow shallow trench isolation trench is formed between the fin pitch of the fins. A wide shallow trench isolation trench is formed at an outside edge of the fins. A doped layer fills the narrow shallow trench isolation trench and the wide shallow trench isolation trench. A vertical thickness of the doped layer in the narrow shallow trench isolation trench is greater than a vertical thickness of the wide shallow trench isolation trench.
    Type: Grant
    Filed: June 15, 2016
    Date of Patent: April 4, 2017
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Michael P. Belyansky, Kangguo Cheng, Ramachandra Divakaruni
  • Patent number: 9608067
    Abstract: A semiconductor structure includes a material stack located on a surface of a semiconductor substrate. The material stack includes, from bottom to top, a silicon germanium alloy portion that is substantially relaxed and defect-free and a semiconductor material pillar that is defect-free. A dielectric material structure surrounds sidewalls of the material stack and is present on exposed portions of the semiconductor substrate.
    Type: Grant
    Filed: March 30, 2015
    Date of Patent: March 28, 2017
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Hong He, Juntao Li
  • Publication number: 20170076999
    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: November 29, 2016
    Publication date: March 16, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim, Juntao Li, Devendra K. Sadana
  • Publication number: 20170076998
    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: November 29, 2016
    Publication date: March 16, 2017
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim, Juntao Li, Devendra K. Sadana
  • Publication number: 20170040320
    Abstract: A bulk semiconductor substrate including a first semiconductor material is provided. A well trapping layer including a second semiconductor material and a dopant is formed on a top surface of the bulk semiconductor substrate. The combination of the second semiconductor material and the dopant within the well trapping layer is selected such that diffusion of the dopant is limited within the well trapping layer. A device semiconductor material layer including a third semiconductor material can be epitaxially grown on the top surface of the well trapping layer. The device semiconductor material layer, the well trapping layer, and an upper portion of the bulk semiconductor substrate are patterned to form at least one semiconductor fin. Semiconductor devices formed in each semiconductor fin can be electrically isolated from the bulk semiconductor substrate by the remaining portions of the well trapping layer.
    Type: Application
    Filed: October 21, 2016
    Publication date: February 9, 2017
    Inventors: Henry K. Utomo, Kangguo Cheng, Ramachandra Divakaruni, Ravikumar Ramachandran, Huiling Shang, Reinaldo A. Vega
  • Patent number: 9559120
    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: July 2, 2015
    Date of Patent: January 31, 2017
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jeehwan Kim, Juntao Li, Devendra K. Sadana