Patents by Inventor Indira Seshadri

Indira Seshadri 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: 11133189
    Abstract: The present disclosure relates to methods and apparatuses related to the deposition of a protective layer selective to an interlayer dielectric layer so that the protective layer is formed onto a top portion associated with the interlayer dielectric layer. In some embodiments, a method comprises: forming an interlayer dielectric layer on a substrate; covering a trench region with a metal liner, wherein the trench region is situated above the substrate and formed within the interlayer dielectric layer; and depositing a protective layer selective to the interlayer dielectric layer so that the protective layer is formed onto a top portion associated with the interlayer dielectric layer. In various embodiments, the depositing the protective layer comprises: repeatedly depositing the protective layer via a multi-deposition sequence; or depositing a self-assembled monolayer onto the top portion.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: September 28, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kisup Chung, Ekmini Anuja De Silva, Andrew Greene, Siva Kanakasabapathy, Indira Seshadri
  • Publication number: 20210296438
    Abstract: Semiconductor devices and methods of forming the same include forming a first dielectric layer around a semiconductor fin, formed from a first dielectric material, to a target height lower than a height of the semiconductor fin. A second dielectric layer is deposited on the first dielectric layer and is formed from a second dielectric material. A third dielectric layer, formed from the first dielectric material, is formed on the second dielectric layer. The second dielectric layer is etched away to expose a gap on the semiconductor fin. A portion of the semiconductor fin that is exposed in the gap is oxidized to form an isolation layer.
    Type: Application
    Filed: June 9, 2021
    Publication date: September 23, 2021
    Inventors: Praveen Joseph, Tao Li, Indira Seshadri, Ekmini A. De Silva
  • Publication number: 20210296314
    Abstract: A semiconductor structure includes a first semiconducting channel having a plurality of vertical nanowires and a second semiconducting channel having a plurality of vertical nanowires. The first semiconducting channel and the second semiconducting channel are configured to be in a stacked configuration. The plurality of vertical nanowires of the first semiconducting channel are configured to be in alternating positions relative to the plurality of vertical nanowires of the second semiconducting channel.
    Type: Application
    Filed: March 17, 2020
    Publication date: September 23, 2021
    Inventors: Tsung-Sheng Kang, Tao Li, Ardasheir Rahman, Praveen Joseph, Indira Seshadri, Ekmini Anuja De Silva
  • Publication number: 20210288164
    Abstract: A technique relates to a semiconductor device. A first epitaxial material is formed under a bottom surface of a set of fins, the first epitaxial material being under fin channel regions of the set of fins. A second epitaxial material is formed adjacent to the first epitaxial material and remote from the fin channel regions, a combination of the first epitaxial material and the second epitaxial material forming a bottom source or drain (source/drain) layer. A top source/drain layer is formed on an upper portion of the set of fins, gate material being disposed around the set of fins between the top source/drain layer and the bottom source/drain layer.
    Type: Application
    Filed: March 10, 2020
    Publication date: September 16, 2021
    Inventors: Tao Li, Indira SESHADRI, NELSON FELIX, ERIC MILLER
  • Patent number: 11121024
    Abstract: A tunable amorphous silicon layer for use with multilayer patterning stacks can be used to maximize transparency and minimize reflections so as to improve overlay metrology contrast. By increasing the hydrogen content in the amorphous silicon layer, the extinction coefficient (k) value and the refractive index (n) value can be decreased to desired values. Methods for improving overlay metrology contrast with the tunable amorphous silicon layer are disclosed.
    Type: Grant
    Filed: August 16, 2019
    Date of Patent: September 14, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Ekmini A. De Silva, Nelson Felix, Indira Seshadri, Stuart A. Sieg
  • Patent number: 11075266
    Abstract: Semiconductor devices and methods of forming the same include forming a first dielectric layer around a semiconductor fin, formed from a first dielectric material, to a target height lower than a height of the semiconductor fin. A second dielectric layer is deposited on the first dielectric layer and is formed from a second dielectric material. A third dielectric layer, formed from the first dielectric material, is formed on the second dielectric layer. The second dielectric layer is etched away to expose a gap on the semiconductor fin. A portion of the semiconductor fin that is exposed in the gap is oxidized to form an isolation layer.
    Type: Grant
    Filed: April 29, 2019
    Date of Patent: July 27, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Praveen Joseph, Tao Li, Indira Seshadri, Ekmini A. De Silva
  • Patent number: 11075081
    Abstract: A method for fabricating a semiconductor device with multiple threshold voltages includes masking a substrate structure to selectively form work-function metal layers on vertical field effect transistors. In the method, a first work function metal layer is formed on a high-k dielectric layer of a substrate structure comprising vertical field effect transistors. The first work function metal layer and the high-k dielectric layer are etched to form gate regions for each vertical field effect transistor. A resist mask is formed over a first of the vertical field effect transistors. The resist mask isolates the first of the vertical field effect transistors from a second of the vertical field effect transistors. A second work function metal layer is selectively formed on the first work function metal layer of the gate region of the second of the vertical field effect transistors. The resist mask is then removed.
    Type: Grant
    Filed: October 21, 2019
    Date of Patent: July 27, 2021
    Assignee: International Business Machines Corporation
    Inventors: Praveen Joseph, Indira Seshadri, Ekmini Anuja De Silva
  • Publication number: 20210118743
    Abstract: Gate metal is removed from a region containing transistors such as nanosheet transistors or vertical transport field-effect transistors using techniques that control the undercutting of gate metal in an adjoining region. A dielectric spacer layer is deposited on the transistors. A first etch causes the removal of gate metal over the boundary between the regions with limited undercutting of gate metal beneath the dielectric spacer layer. A subsequent etch removes the gate metal from the transistors in one region while the gate metal in the adjoining region is protected by a buffer layer. Gate dielectric material may also be removed over the boundary between regions.
    Type: Application
    Filed: December 30, 2020
    Publication date: April 22, 2021
    Inventors: Romain Lallement, Indira Seshadri, Ruqiang Bao
  • Patent number: 10985025
    Abstract: Methods for forming semiconductor fins include forming a protective layer around a base of a hardmask fin on an underlying semiconductor layer. A portion of the hardmask fin is etched away with an etch that is selective to the protective layer. A semiconductor fin is etched from the semiconductor layer using the etched hardmask fin as a mask.
    Type: Grant
    Filed: October 29, 2018
    Date of Patent: April 20, 2021
    Assignee: International Business Machines Corporation
    Inventors: Eric R. Miller, Stuart A. Sieg, Yann Mignot, Indira Seshadri, Christopher J. Waskiewicz
  • Patent number: 10903124
    Abstract: Gate metal is removed from a region containing transistors such as nanosheet transistors or vertical transport field-effect transistors using techniques that control the undercutting of gate metal in an adjoining region. A dielectric spacer layer is deposited on the transistors. A first etch causes the removal of gate metal over the boundary between the regions with limited undercutting of gate metal beneath the dielectric spacer layer. A subsequent etch removes the gate metal from the transistors in one region while the gate metal in the adjoining region is protected by a buffer layer. Gate dielectric material may also be removed over the boundary between regions.
    Type: Grant
    Filed: April 30, 2019
    Date of Patent: January 26, 2021
    Assignee: International Business Machines Corporation
    Inventors: Romain Lallement, Indira Seshadri, Ruqiang Bao
  • Patent number: 10832945
    Abstract: Techniques to improve CD width and depth uniformity between features with different layout densities are provided. In one aspect, a method of forming a contact structure includes: patterning features in different regions of a dielectric at different layout densities whereby, due to etch loading effects, the features are patterned to different depths in the dielectric and have different bottom dimensions; depositing a sacrificial spacer into/lining the features whereby some of the features are pinched-off by the sacrificial spacer; opening up the sacrificial spacer at bottoms of one or more of the features that are not pinched-off by the sacrificial spacer; selectively extending the one or more features in the dielectric, such that the one or more features have a discontinuous taper with a stepped sidewall profile; removing the sacrificial spacer; and filling the features with a conductive material to form the contact structure. A contact structure is also provided.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: November 10, 2020
    Assignee: International Business Machines Corporation
    Inventors: Nicole Saulnier, Indira Seshadri, Lawrence A. Clevenger, Leigh Anne H. Clevenger, Gauri Karve, Fee Li Lie, Isabel Cristina Chu, Hosadurga Shobha, Ekmini A. De Silva
  • Publication number: 20200350212
    Abstract: Gate metal is removed from a region containing transistors such as nanosheet transistors or vertical transport field-effect transistors using techniques that control the undercutting of gate metal in an adjoining region. A dielectric spacer layer is deposited on the transistors. A first etch causes the removal of gate metal over the boundary between the regions with limited undercutting of gate metal beneath the dielectric spacer layer. A subsequent etch removes the gate metal from the transistors in one region while the gate metal in the adjoining region is protected by a buffer layer. Gate dielectric material may also be removed over the boundary between regions.
    Type: Application
    Filed: April 30, 2019
    Publication date: November 5, 2020
    Inventors: Romain Lallement, Indira Seshadri, Ruqiang Bao
  • Publication number: 20200343338
    Abstract: Semiconductor devices and methods of forming the same include forming a first dielectric layer around a semiconductor fin, formed from a first dielectric material, to a target height lower than a height of the semiconductor fin. A second dielectric layer is deposited on the first dielectric layer and is formed from a second dielectric material. A third dielectric layer, formed from the first dielectric material, is formed on the second dielectric layer. The second dielectric layer is etched away to expose a gap on the semiconductor fin. A portion of the semiconductor fin that is exposed in the gap is oxidized to form an isolation layer.
    Type: Application
    Filed: April 29, 2019
    Publication date: October 29, 2020
    Inventors: Praveen Joseph, Tao Li, Indira Seshadri, Ekmini A. De Silva
  • Patent number: 10818751
    Abstract: Embodiments of the invention are directed to a nanosheet field effect transistor (FET) device. A non-limiting example of the nanosheet FET device includes a stack of channel nanosheets over a substrate, along with a source or drain (S/D) trench in a predetermined region of the substrate. The predetermined region of the substrate includes a region over which a S/D region of the nanosheet FET is formed. The S/D region of the nanosheet FET is formed at ends of a bottommost one of the stack of channel nanosheets. An isolation barrier is formed in the S/D trench. The isolation barrier is configured to substantially prevent the S/D region from being electrically coupled to the substrate.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: October 27, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Mona A. Ebrish, Fee Li Lie, Nicolas Loubet, Gauri Karve, Indira Seshadri, Lawrence A. Clevenger, Leigh Anne H. Clevenger
  • Patent number: 10804106
    Abstract: Techniques for providing a high temperature soft mask for semiconductor devices are described. In an embodiment, spin coating semiconductor device components with organic planarization material having a defined aromatic content aromatic content to provide an organic planarization layer. The method can further comprise ultra-fast annealing the organic planarization layer and forming an implanted or doped region in the semiconductor device. Three-dimensional FinFET components of a device can be spin coated with organic planarization material having high aromatic content, with the device cured at a first temperature. The organic planarization layer can be ultra-fast annealed at a second temperature that is greater than the first temperature. Aspects can include patterning the device, and forming an implanted or doped region in a semiconductor device.
    Type: Grant
    Filed: February 21, 2018
    Date of Patent: October 13, 2020
    Assignee: International Business Machines Corporation
    Inventors: Mona Ebrish, Oleg Gluschenkov, Indira Seshadri, Ekmini Anuja De Silva
  • Publication number: 20200279913
    Abstract: Embodiments of the invention are directed to a nanosheet field effect transistor (FET) device. A non-limiting example of the nanosheet FET device includes a stack of channel nanosheets over a substrate, along with a source or drain (S/D) trench in a predetermined region of the substrate. The predetermined region of the substrate includes a region over which a S/D region of the nanosheet FET is formed. The S/D region of the nanosheet FET is formed at ends of a bottommost one of the stack of channel nanosheets. An isolation barrier is formed in the S/D trench. The isolation barrier is configured to substantially prevent the S/D region from being electrically coupled to the substrate.
    Type: Application
    Filed: March 1, 2019
    Publication date: September 3, 2020
    Inventors: Mona A. Ebrish, Fee Li Lie, Nicolas Loubet, Gauri Karve, Indira Seshadri, Lawrence A. Clevenger, Leigh Anne H. Clevenger
  • Publication number: 20200279956
    Abstract: A semiconductor structure and a method for fabricating the same. The semiconductor structure includes at least a first channel region and a second channel region. The first channel region and the second channel region each include metal gate structures surrounding a different nanosheet channel layer. The metal gate structures of the first and second channel regions are respectively separated from each other by an unfilled gap. The method includes forming a gap fill layer between and in contact with gate structures surrounding nanosheet channel layers in multiple channel regions. Then, after the gap fill layer has been formed for each nanosheet stack, a masking layer is formed over the gate structures and the gap fill layer in at least a first channel region. The gate structures and the gap fill layer in at least a second channel region remain exposed.
    Type: Application
    Filed: May 19, 2020
    Publication date: September 3, 2020
    Inventors: Indira SESHADRI, Ekmini Anuja DE SILVA, Jing GUO, Ruqiang BAO, Muthumanickam SANKARAPANDIAN, Nelson FELIX
  • Publication number: 20200266100
    Abstract: Techniques to improve CD width and depth uniformity between features with different layout densities are provided. In one aspect, a method of forming a contact structure includes: patterning features in different regions of a dielectric at different layout densities whereby, due to etch loading effects, the features are patterned to different depths in the dielectric and have different bottom dimensions; depositing a sacrificial spacer into/lining the features whereby some of the features are pinched-off by the sacrificial spacer; opening up the sacrificial spacer at bottoms of one or more of the features that are not pinched-off by the sacrificial spacer; selectively extending the one or more features in the dielectric, such that the one or more features have a discontinuous taper with a stepped sidewall profile; removing the sacrificial spacer; and filling the features with a conductive material to form the contact structure. A contact structure is also provided.
    Type: Application
    Filed: February 15, 2019
    Publication date: August 20, 2020
    Inventors: Nicole Saulnier, Indira Seshadri, Lawrence A. Clevenger, Leigh Anne H. Clevenger, Gauri Karve, Fee Li Lie, Isabel Cristina Chu, Hosadurga Shobha, Ekmini A. De Silva
  • Patent number: 10741454
    Abstract: Methods are presented for forming multi-threshold field effect transistors. The methods generally include depositing and patterning an organic planarizing layer to protect underlying structures formed in a selected one of the nFET region and the pFET region of a semiconductor wafer. In the other one of the nFET region and the pFET region, structures are processed to form an undercut in the organic planarizing layer. The organic planarizing layer is subjected to a reflow process to fill the undercut. The methods are effective to protect a boundary between the nFET region and the pFET region.
    Type: Grant
    Filed: August 9, 2018
    Date of Patent: August 11, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jing Guo, Ekmini A. De Silva, Nicolas Loubet, Indira Seshadri, Nelson Felix
  • Patent number: 10741452
    Abstract: Methods for forming semiconductor fins include forming a sacrificial semiconductor structure around a hardmask fin on an underlying semiconductor layer. A first etch is performed that partially etches away a portion of the hardmask fin and the sacrificial semiconductor structure with a first etch chemistry. A second etch is performed that etches away remaining material of the portion of the hardmask fin and partially etches remaining material of the sacrificial semiconductor structure with a second etch chemistry. A semiconductor fin is etched from the semiconductor layer using the etched hardmask fin as a mask.
    Type: Grant
    Filed: October 29, 2018
    Date of Patent: August 11, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Eric R. Miller, Stuart A. Sieg, Yann Mignot, Indira Seshadri, Christopher J. Waskiewicz