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).

  • Publication number: 20200075761
    Abstract: A semiconductor device includes a semiconductor fin that extends from a first source/drain to an opposing second source/drain. The semiconductor fin includes a channel region between the first and second source/drains. The semiconductor device further includes a spacer having an upper surface having the second source/drain formed thereon, and a gate structure a gate structure wrapping around the channel region. The gate structure includes a tapered portion that contacts the spacer.
    Type: Application
    Filed: August 28, 2018
    Publication date: March 5, 2020
    Inventors: Praveen Joseph, Indira Seshadri, Ekmini A. De Silva, Stuart A. Sieg
  • Publication number: 20200052107
    Abstract: A method of forming a nanosheet device is provided. The method includes forming a nanosheet channel layer stack and dummy gate structure on a substrate. The method further includes forming a curved recess in the substrate surface adjacent to the nanosheet channel layer stack. The method further includes depositing a protective layer on the curved recess, dummy gate structure, and exposed sidewall surfaces of the nanosheet layer stack, and removing a portion of the protective layer on the curved recess to form a downward-spiked ridge around the rim of the curved recess. The method further includes extending the curved recess deeper into the substrate to form an extended recess, and forming a sacrificial layer at the surface of the extended recess in the substrate.
    Type: Application
    Filed: August 13, 2018
    Publication date: February 13, 2020
    Inventors: Fee Li Lie, Mona Ebrish, Ekmini A. De Silva, Indira Seshadri, Gauri Karve, Lawrence A. Clevenger, Leigh Anne H. Clevenger, Nicolas Loubet
  • Publication number: 20200051872
    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: Application
    Filed: August 9, 2018
    Publication date: February 13, 2020
    Inventors: Jing Guo, Ekmini A. De Silva, Nicolas Loubet, Indira Seshadri, Nelson Felix
  • Publication number: 20200050113
    Abstract: A semiconductor structure comprises a semiconductor substrate, and a multi-layer patterning material film stack formed on the semiconductor substrate. The patterning material film stack comprises at least a hard mask layer and a resist layer formed over the hard mask layer. The hard mask layer is configured to support selective deposition of a metal-containing layer on a developed pattern of the resist layer through inclusion in the hard mask layer of one or more materials inhibiting deposition of the metal-containing layer on portions of the hard mask layer corresponding to respective openings in the resist layer. The hard mask layer illustratively comprises, for example, at least one of a grafted self-assembled monolayer configured to inhibit deposition of the metal-containing layer, and a grafted polymer brush material configured to inhibit deposition of the metal-containing layer.
    Type: Application
    Filed: October 18, 2019
    Publication date: February 13, 2020
    Inventors: Ekmini Anuja De Silva, Indira Seshadri, Jing Guo, Ashim Dutta, Nelson Felix
  • Publication number: 20200050108
    Abstract: A self-priming resist may be formed from a first random copolymer forming a resist and a polymer brush having the general formula poly(A-r-B)-C-D, wherein A is a first polymer unit, B is a second polymer unit, wherein A and B are the same or different polymer units, C is a cleavable unit, D is a grafting group and r indicates that poly(A-r-B) is a second random copolymer formed from the first and second polymer units. The first random copolymer may be the same or different from the second random polymer. The self-priming resist can create a one-step method for forming an adhesion layer and resist by using the resist/brush blend.
    Type: Application
    Filed: August 11, 2018
    Publication date: February 13, 2020
    Inventors: Chi-Chun Liu, Indira Seshadri, Kristin Schmidt, Nelson Felix, Daniel Sanders, Jing Guo, Ekmini Anuja De Silva, Hoa Truong
  • Publication number: 20190371651
    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: Application
    Filed: August 16, 2019
    Publication date: December 5, 2019
    Inventors: Ekmini A. De Silva, Nelson Felix, Indira Seshadri, Stuart A. Sieg
  • Publication number: 20190355851
    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 15, 2018
    Publication date: November 21, 2019
    Inventors: Indira SESHADRI, Ekmini Anuja DE SILVA, Jing GUO, Ruqiang BAO, Muthumanickam SANKARAPANDIAN, Nelson FELIX
  • Publication number: 20190355625
    Abstract: Various methods and structures for fabricating a plurality of vertical fins in a vertical fin pattern on a semiconductor substrate where the vertical fins in the vertical fin pattern are separated by wide-open spaces, along a critical dimension, in a low duty cycle of 1:5 or lower. Adjacent vertical fins in the vertical fin pattern can be all separated by respective wide-open spaces, along a critical dimension, in a low duty cycle, and wherein pairs of adjacent vertical fins in the vertical fin pattern, along the critical dimension, are separated by a constant pitch value at near zero tolerance.
    Type: Application
    Filed: May 8, 2019
    Publication date: November 21, 2019
    Inventors: Praveen JOSEPH, Ekmini Anuja DE SILVA, Fee Li LIE, Stuart A. SIEG, Yann MIGNOT, Indira SESHADRI
  • Publication number: 20190295841
    Abstract: Embodiments of the present invention are directed to the wet stripping of an organic planarization layer (OPL) using reversible UV crosslinking and de-crosslinking. In a non-limiting embodiment of the invention, an interlayer dielectric is formed over a substrate. A trench is formed in the interlayer dielectric. A work function metal is formed over the interlayer dielectric such that a portion of the work function metal partially fills the trench. A UV sensitive OPL is formed over the work function metal such that a portion of the UV sensitive OPL fills the trench. The UV sensitive OPL can be crosslinked by applying light at a first UV frequency and de-crosslinked by applying light at a second UV frequency.
    Type: Application
    Filed: May 29, 2019
    Publication date: September 26, 2019
    Inventors: Ekmini A. De Silva, Nelson Felix, Jing Guo, Indira Seshadri
  • Patent number: 10395925
    Abstract: A lithographic patterning method includes forming a multi-layer patterning material film stack on a semiconductor substrate. Forming the patterning material film stack includes forming a hard mask layer and forming a resist layer over the hard mask layer. The hard mask layer is formed such that an interface portion of the hard mask layer proximate the resist layer has a higher metal content than other portions of the hard mask layer. The method further includes exposing the patterning material film stack to patterning radiation to form a desired pattern in the resist layer, developing the pattern formed in the resist layer, etching the hard mask layer in accordance with the developed pattern, and removing remaining portions of the resist layer. The hard mask layer illustratively includes metal oxide, metal nitride and/or metal oxynitride, and may exhibit an elevated surface hydrophobicity due to its high metal content interface portion.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: August 27, 2019
    Assignee: International Business Machines Corporation
    Inventors: Ekmini Anuja De Silva, Adra Carr, Shanti Pancharatnam, Indira Seshadri, Yasir Sulehria
  • Publication number: 20190259616
    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: Application
    Filed: February 21, 2018
    Publication date: August 22, 2019
    Inventors: Mona Ebrish, Oleg Gluschenkov, Indira Seshadri, Ekmini Anuja De Silva
  • Patent number: 10388510
    Abstract: Embodiments of the present invention are directed to the wet stripping of an organic planarization layer (OPL) using reversible UV crosslinking and de-crosslinking. In a non-limiting embodiment of the invention, an interlayer dielectric is formed over a substrate. A trench is formed in the interlayer dielectric. A work function metal is formed over the interlayer dielectric such that a portion of the work function metal partially fills the trench. A UV sensitive OPL is formed over the work function metal such that a portion of the UV sensitive OPL fills the trench. The UV sensitive OPL can be crosslinked by applying light at a first UV frequency and de-crosslinked by applying light at a second UV frequency.
    Type: Grant
    Filed: January 12, 2018
    Date of Patent: August 20, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Ekmini A. De Silva, Nelson Felix, Jing Guo, Indira Seshadri
  • Patent number: 10361127
    Abstract: A method for forming a device with multiple gate lengths includes forming a gate stack on vertical fins. A cutting mask formed on the gate stack is etched to include two or more different heights. Gate structures with two or more gate lengths are etched by employing the two or more different heights in the cutting mask as an etch mask. The cutting mask is removed. A top source/drain regions is formed on top of the vertical fins.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: July 23, 2019
    Assignee: International Business Machines Corporation
    Inventors: Gauri Karve, Fee Li Lie, Indira Seshadri, Mona Ebrish, Leigh Anne H. Clevenger, Ekmini A. De Silva, Nicole A. Saulnier
  • Patent number: 10361129
    Abstract: Methods and devices for forming multiple fin lengths includes forming a material stack on vertical fins. A plurality of mandrels are formed on the material stack. Spacers are formed along the plurality of mandrels with the spacers width being a length of short fins. One or more of the plurality of mandrels are removed. The material stack is patterned to form the short fins beneath the spacers and long fins. The vertical fins are cut with the pattern of the material stack to form the short fins and the long fins.
    Type: Grant
    Filed: May 18, 2018
    Date of Patent: July 23, 2019
    Assignee: International Business Machines Corporation
    Inventors: Stuart A. Sieg, Yann Mignot, Christopher J. Waskiewicz, Hemanth Jagannathan, Eric Miller, Indira Seshadri
  • Publication number: 20190221423
    Abstract: Embodiments of the present invention are directed to the wet stripping of an organic planarization layer (OPL) using reversible UV crosslinking and de-crosslinking. In a non-limiting embodiment of the invention, an interlayer dielectric is formed over a substrate. A trench is formed in the interlayer dielectric. A work function metal is formed over the interlayer dielectric such that a portion of the work function metal partially fills the trench. A UV sensitive OPL is formed over the work function metal such that a portion of the UV sensitive OPL fills the trench. The UV sensitive OPL can be crosslinked by applying light at a first UV frequency and de-crosslinked by applying light at a second UV frequency.
    Type: Application
    Filed: January 12, 2018
    Publication date: July 18, 2019
    Inventors: Ekmini A. De Silva, Nelson Felix, Jing Guo, Indira Seshadri
  • Patent number: 10354922
    Abstract: Semiconductor devices and methods of forming the same include forming a wet-strippable hardmask over semiconductor fins. The wet-strippable hardmask is anisotropically etched away in a first device region. At least one semiconductor fin is doped in the first device region. The wet-strippable hardmask is isotropically etched away in a second device region. Semiconductor devices are formed from the fins in the first and second device regions.
    Type: Grant
    Filed: December 27, 2017
    Date of Patent: July 16, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Ekmini Anuja De Silva, Indira Seshadri, Romain Lallement, Nelson Felix
  • Publication number: 20190214311
    Abstract: A semiconductor structure comprises a semiconductor substrate, an N-type stacked nanosheet channel structure formed on the semiconductor substrate, and a P-type stacked nanosheet channel structure formed adjacent to the N-type stacked nanosheet channel structure on the semiconductor substrate. Each of the adjacent N-type and P-type stacked nanosheet channel structures comprises a plurality of stacked channel regions with each such channel region being substantially surrounded by a gate dielectric layer and a gate work function metal layer, and with the gate work function metal layer being separated from the channel regions by the gate dielectric layer. The gate dielectric and gate work function metal layers of the adjacent N-type and P-type stacked nanosheet channel structures are substantially eliminated from a shared gate region between the adjacent N-type and P-type stacked nanosheet channel structures.
    Type: Application
    Filed: January 7, 2019
    Publication date: July 11, 2019
    Inventors: Indira Seshadri, Ekmini Anuja De Silva, Jing Guo, Romain J. Lallement, Ruqiang Bao, Zhenxing Bi, Sivananda Kanakasabapathy
  • Publication number: 20190206681
    Abstract: A lithographic patterning method includes forming a multi-layer patterning material film stack on a semiconductor substrate. Forming the patterning material film stack includes forming a hard mask layer and forming a resist layer over the hard mask layer. The hard mask layer is formed such that an interface portion of the hard mask layer proximate the resist layer has a higher metal content than other portions of the hard mask layer. The method further includes exposing the patterning material film stack to patterning radiation to form a desired pattern in the resist layer, developing the pattern formed in the resist layer, etching the hard mask layer in accordance with the developed pattern, and removing remaining portions of the resist layer. The hard mask layer illustratively includes metal oxide, metal nitride and/or metal oxynitride, and may exhibit an elevated surface hydrophobicity due to its high metal content interface portion.
    Type: Application
    Filed: December 28, 2017
    Publication date: July 4, 2019
    Inventors: Ekmini Anuja De Silva, Adra Carr, Shanti Pancharatnam, Indira Seshadri, Yasir Sulehria
  • Publication number: 20190206738
    Abstract: A method for forming a device with multiple gate lengths includes forming a gate stack on vertical fins. A cutting mask formed on the gate stack is etched to include two or more different heights. Gate structures with two or more gate lengths are etched by employing the two or more different heights in the cutting mask as an etch mask. The cutting mask is removed. A top source/drain regions is formed on top of the vertical fins.
    Type: Application
    Filed: December 28, 2017
    Publication date: July 4, 2019
    Inventors: Gauri Karve, Fee Li Lie, Indira Seshadri, Mona Ebrish, Leigh Anne H. Clevenger, Ekmini A. De Silva, Nicole A. Saulnier
  • Publication number: 20190206722
    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: Application
    Filed: January 4, 2018
    Publication date: July 4, 2019
    Inventors: Ekmini A. De Silva, Nelson Felix, Indira Seshadri, Stuart A. Sieg