Patents by Inventor Thamarai S. Devarajan

Thamarai S. Devarajan 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: 11302797
    Abstract: A vertical transport fin field effect transistor (VT FinFET), including one or more vertical fins on a surface of a substrate, an L-shaped or U-shaped spacer trough on the substrate adjacent to at least one of the one or more vertical fins, and a gate dielectric layer on the sidewalls of the at least one of the one or more vertical fins and the L-shaped or U-shaped spacer trough.
    Type: Grant
    Filed: February 24, 2020
    Date of Patent: April 12, 2022
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan, Sanjay C. Mehta, Muthumanickam Sankarapandian
  • Patent number: 10896816
    Abstract: A method for forming a nanosheet semiconductor device includes forming a nanosheet stack comprising channel nanosheets. The method includes depositing silicon on the nanosheet stack, the silicon completely filling a space between adjacent channel nanosheets. The method includes etching the silicon. The method includes exposing the nanosheet stack to a gas phase heat treatment.
    Type: Grant
    Filed: September 26, 2017
    Date of Patent: January 19, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Nicolas J. Loubet, Binglin Miao, Muthumanickam Sankarapandian, Charan V. Surisetty, Chun W. Yeung, Jingyun Zhang
  • Patent number: 10840354
    Abstract: A vertical transport fin field effect transistor (VT FinFET), including one or more vertical fins on a surface of a substrate, an L-shaped or U-shaped spacer trough on the substrate adjacent to at least one of the one or more vertical fins, and a gate dielectric layer on the sidewalls of the at least one of the one or more vertical fins and the L-shaped or U-shaped spacer trough.
    Type: Grant
    Filed: February 6, 2017
    Date of Patent: November 17, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan, Sanjay C. Mehta, Muthumanickam Sankarapandian
  • Publication number: 20200212202
    Abstract: A vertical transport fin field effect transistor (VT FinFET), including one or more vertical fins on a surface of a substrate, an L-shaped or U-shaped spacer trough on the substrate adjacent to at least one of the one or more vertical fins, and a gate dielectric layer on the sidewalls of the at least one of the one or more vertical fins and the L-shaped or U-shaped spacer trough.
    Type: Application
    Filed: February 24, 2020
    Publication date: July 2, 2020
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan, Sanjay C. Mehta, Muthumanickam Sankarapandian
  • Patent number: 10629702
    Abstract: A vertical transport fin field effect transistor (VT FinFET), including one or more vertical fins on a surface of a substrate, an L-shaped or U-shaped spacer trough on the substrate adjacent to at least one of the one or more vertical fins, and a gate dielectric layer on the sidewalls of the at least one of the one or more vertical fins and the L-shaped or U-shaped spacer trough.
    Type: Grant
    Filed: January 3, 2018
    Date of Patent: April 21, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan, Sanjay C. Mehta, Muthumanickam Sankarapandian
  • Patent number: 10388571
    Abstract: A semiconductor device that includes a first plurality of fin structures in a first device region and a second plurality of fin structures in a second device region. The first plurality of fin structures includes adjacent fin structures separated by a lesser pitch than the adjacent fin structures in the second plurality of fin structures. At least one layer of dielectric material between adjacent fin structures, wherein a portion of the first plurality of fin structures extending above the at least one layer of dielectric material in the first device region is substantially equal to the portion of the second plurality of fin structures extending above the at least one layer of dielectric material in the second device region. Source and drain regions are present on opposing sides of a gate structure that is present on the fin structures.
    Type: Grant
    Filed: May 17, 2018
    Date of Patent: August 20, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Zhenxing Bi, Kangguo Cheng, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan
  • Patent number: 10366928
    Abstract: A semiconductor device having a uniform height across different fin densities includes a semiconductor substrate having fins etched therein and including dense fin regions and isolation regions without fins. One or more dielectric layers are formed at a base of the fins and the isolation regions and have a uniform height across the fins and the isolation regions. The uniform height includes a less than 2 nanometer difference across the one or more dielectric layers.
    Type: Grant
    Filed: February 15, 2017
    Date of Patent: July 30, 2019
    Assignee: International Business Machines Corporation
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sivananda K. Kanakasabapathy, Fee Li Lie, Peng Xu
  • Publication number: 20190096669
    Abstract: A method for forming a nanosheet semiconductor device includes forming a nanosheet stack comprising channel nanosheets. The method includes depositing silicon on the nanosheet stack, the silicon completely filling a space between adjacent channel nanosheets. The method includes etching the silicon. The method includes exposing the nanosheet stack to a gas phase heat treatment.
    Type: Application
    Filed: September 26, 2017
    Publication date: March 28, 2019
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Nicolas J. Loubet, Binglin Miao, Muthumanickam Sankarapandian, Charan V. Surisetty, Chun W. Yeung, Jingyun Zhang
  • Patent number: 10242882
    Abstract: Methods are provided to implement a cyclic etch process to remove oxide layers for semiconductor device fabrication. For example, a method comprises performing a cyclic etch process to incrementally etch an oxide layer, wherein the cyclic etch process comprises sequentially performing at least two instances of an etch cycle. The etch cycle comprises performing an etch process to partially etch a portion of the oxide layer using an etch chemistry and environment which is configured to etch down the oxide layer at an etch rate of about 25 angstroms/minute or less, and performing a thermal treatment to remove by-products of the etch process. The cyclic etch process can be implemented as part of a replacement metal gate process to remove a dummy gate oxide layer of a dummy gate structure as part of, e.g., a FinFET semiconductor fabrication process flow.
    Type: Grant
    Filed: June 12, 2017
    Date of Patent: March 26, 2019
    Assignee: International Business Machines Corporation
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sean Teehan
  • Patent number: 10163721
    Abstract: A method for uniform fin reveal depth for semiconductor devices includes dry etching a dielectric material to reveal semiconductor fins by a quasi-atomic layer etching (quasi-ALE) process to achieve depth uniformity across different fin pitches. A lateral bias induced by the quasi-ALE process is compensated for by isotropically etching the dielectric material.
    Type: Grant
    Filed: September 28, 2017
    Date of Patent: December 25, 2018
    Assignee: International Business Machines Corporation
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sivananda K. Kanakasabapathy, Fee Li Lie, Peng Xu
  • Publication number: 20180358232
    Abstract: Methods are provided to implement a cyclic etch process to remove oxide layers for semiconductor device fabrication. For example, a method comprises performing a cyclic etch process to incrementally etch an oxide layer, wherein the cyclic etch process comprises sequentially performing at least two instances of an etch cycle. The etch cycle comprises performing an etch process to partially etch a portion of the oxide layer using an etch chemistry and environment which is configured to etch down the oxide layer at an etch rate of about 25 angstroms/minute or less, and performing a thermal treatment to remove by-products of the etch process. The cyclic etch process can be implemented as part of a replacement metal gate process to remove a dummy gate oxide layer of a dummy gate structure as part of, e.g., a FinFET semiconductor fabrication process flow.
    Type: Application
    Filed: June 12, 2017
    Publication date: December 13, 2018
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sean Teehan
  • Publication number: 20180269108
    Abstract: A semiconductor device that includes a first plurality of fin structures in a first device region and a second plurality of fin structures in a second device region. The first plurality of fin structures includes adjacent fin structures separated by a lesser pitch than the adjacent fin structures in the second plurality of fin structures. At least one layer of dielectric material between adjacent fin structures, wherein a portion of the first plurality of fin structures extending above the at least one layer of dielectric material in the first device region is substantially equal to the portion of the second plurality of fin structures extending above the at least one layer of dielectric material in the second device region. Source and drain regions are present on opposing sides of a gate structure that is present on the fin structures.
    Type: Application
    Filed: May 17, 2018
    Publication date: September 20, 2018
    Inventors: Zhenxing Bi, Kangguo Cheng, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan
  • Publication number: 20180226491
    Abstract: A vertical transport fin field effect transistor (VT FinFET), including one or more vertical fins on a surface of a substrate, an L-shaped or U-shaped spacer trough on the substrate adjacent to at least one of the one or more vertical fins, and a gate dielectric layer on the sidewalls of the at least one of the one or more vertical fins and the L-shaped or U-shaped spacer trough.
    Type: Application
    Filed: January 3, 2018
    Publication date: August 9, 2018
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan, Sanjay C. Mehta, Muthumanickam Sankarapandian
  • Publication number: 20180226489
    Abstract: A vertical transport fin field effect transistor (VT FinFET), including one or more vertical fins on a surface of a substrate, an L-shaped or U-shaped spacer trough on the substrate adjacent to at least one of the one or more vertical fins, and a gate dielectric layer on the sidewalls of the at least one of the one or more vertical fins and the L-shaped or U-shaped spacer trough.
    Type: Application
    Filed: February 6, 2017
    Publication date: August 9, 2018
    Inventors: Zhenxing Bi, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan, Sanjay C. Mehta, Muthumanickam Sankarapandian
  • Patent number: 10020229
    Abstract: A semiconductor device that includes a first plurality of fin structures in a first device region and a second plurality of fin structures in a second device region. The first plurality of fin structures includes adjacent fin structures separated by a lesser pitch than the adjacent fin structures in the second plurality of fin structures. At least one layer of dielectric material between adjacent fin structures, wherein a portion of the first plurality of fin structures extending above the at least one layer of dielectric material in the first device region is substantially equal to the portion of the second plurality of fin structures extending above the at least one layer of dielectric material in the second device region. Source and drain regions are present on opposing sides of a gate structure that is present on the fin structures.
    Type: Grant
    Filed: April 14, 2017
    Date of Patent: July 10, 2018
    Assignee: International Business Machines Corporation
    Inventors: Zhenxing Bi, Kangguo Cheng, Thamarai S. Devarajan, Balasubramanian Pranatharthiharan
  • Patent number: 9997352
    Abstract: A method is presented for forming a semiconductor device. The method includes depositing a sacrificial layer on a fin structure formed on a substrate and then filled with polysilicon, etching a portion of the polysilicon material via a first etching process, and pre-cleaning the surface native oxide layer. The method further includes etching the remaining polysilicon material via a second etching process, and removing polysilicon etch residue formed adjacent the fin structure by a cleaning process. The pre-cleaning is performed by applying ammonia (NH3) and nitrogen trifluoride (NF3) or by applying buffered hydrofluoric acid (BHF). The first etching process is reactive ion etching (RIE) and the second etching process involves applying nitrogen trifluoride (NF3) and hydrogen gas (H2).
    Type: Grant
    Filed: March 22, 2017
    Date of Patent: June 12, 2018
    Assignee: International Business Machines Corporation
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Nicolas J. Loubet
  • Patent number: 9935015
    Abstract: A method for uniform fin reveal depth for semiconductor devices includes dry etching a dielectric material to reveal semiconductor fins by a quasi-atomic layer etching (quasi-ALE) process to achieve depth uniformity across different fin pitches. A lateral bias induced by the quasi-ALE process is compensated for by isotropically etching the dielectric material.
    Type: Grant
    Filed: April 4, 2017
    Date of Patent: April 3, 2018
    Assignee: International Business Machines Corporation
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sivananda K. Kanakasabapathy, Fee Li Lie, Peng Xu
  • Publication number: 20180090367
    Abstract: A semiconductor device having a uniform height across different fin densities includes a semiconductor substrate having fins etched therein and including dense fin regions and isolation regions without fins. One or more dielectric layers are formed at a base of the fins and the isolation regions and have a uniform height across the fins and the isolation regions. The uniform height includes a less than 2 nanometer difference across the one or more dielectric layers.
    Type: Application
    Filed: February 15, 2017
    Publication date: March 29, 2018
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sivananda K. Kanakasabapathy, Fee Li Lie, Peng Xu
  • Publication number: 20180090385
    Abstract: A method for uniform fin reveal depth for semiconductor devices includes dry etching a dielectric material to reveal semiconductor fins by a quasi-atomic layer etching (quasi-ALE) process to achieve depth uniformity across different fin pitches. A lateral bias induced by the quasi-ALE process is compensated for by isotropically etching the dielectric material.
    Type: Application
    Filed: September 28, 2017
    Publication date: March 29, 2018
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sivananda K. Kanakasabapathy, Fee Li Lie, Peng Xu
  • Publication number: 20180090384
    Abstract: A method for uniform fin reveal depth for semiconductor devices includes dry etching a dielectric material to reveal semiconductor fins by a quasi-atomic layer etching (quasi-ALE) process to achieve depth uniformity across different fin pitches. A lateral bias induced by the quasi-ALE process is compensated for by isotropically etching the dielectric material.
    Type: Application
    Filed: April 4, 2017
    Publication date: March 29, 2018
    Inventors: Zhenxing Bi, Donald F. Canaperi, Thamarai S. Devarajan, Sivananda K. Kanakasabapathy, Fee Li Lie, Peng Xu