Patents by Inventor Mahalingam Nandakumar

Mahalingam Nandakumar 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: 20230095534
    Abstract: A channel stop and well dopant migration control implant (e.g., of argon) can be used in the fabrication of a transistor (e.g., PMOS), either around the time of threshold voltage adjust and well implants prior to gate formation, or as a through-gate implant around the time of source/drain extension implants. With its implant depth targeted about at or less than the peak of the concentration of the dopant used for well and channel stop implants (e.g., phosphorus) and away from the substrate surface, the migration control implant suppresses the diffusion of the well and channel stop dopant to the surface region, a more retrograde concentration profile is achieved, and inter-transistor threshold voltage mismatch is improved without other side effects. A compensating through-gate threshold voltage adjust implant (e.g., of arsenic) or a threshold voltage adjust implant of increased dose can increase the magnitude of the threshold voltage to a desired level.
    Type: Application
    Filed: September 30, 2021
    Publication date: March 30, 2023
    Inventor: MAHALINGAM NANDAKUMAR
  • Patent number: 11616058
    Abstract: The present disclosure provides a method for forming a semiconductor device containing MOS transistors both with and without source/drain extension regions in a semiconductor substrate having a semiconductor material on either side of a gate structure including a gate electrode on a gate dielectric formed in a semiconductor material. In devices with source/drain extensions, a diffusion suppression species of one or more of indium, carbon and a halogen are used. The diffusion suppression implant can be selectively provided only to the semiconductor devices with drain extensions while devices without drain extensions remain diffusion suppression implant free.
    Type: Grant
    Filed: December 10, 2020
    Date of Patent: March 28, 2023
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Brian Edward Hornung
  • Patent number: 11588008
    Abstract: An integrated circuit includes a polysilicon resistor having a plurality of segments, including first, second and third segments, the second segment located between and running about parallel to the first and third segments. A first header connects the first and second segments, and a second header connects the second and third segments. A first metal silicide layer located over the first header extends over the first and second segments toward the second header. A second metal silicide layer located over the second header extends over the second and third segments toward the first header. A dielectric layer is located over and contacts the first, second and third segments between the first and second metal silicide layers.
    Type: Grant
    Filed: February 25, 2020
    Date of Patent: February 21, 2023
    Assignee: Texas Instruments Incorporated
    Inventor: Mahalingam Nandakumar
  • Patent number: 11581399
    Abstract: Methods and semiconductor circuits are described in which a polysilicon resistor body is formed over a semiconductor substrate. A first dopant species is implanted into the polysilicon resistor body at a first angle about parallel to a surface normal of a topmost surface of the polysilicon resistor body. A second dopant species is implanted into the polysilicon resistor body at a second angle greater than about 10° relative to the surface normal. The combination of implants reduces the different between the temperature coefficient (tempco) of resistance of narrow resistors relative to the tempco of wide resistors, and brings the tempco of the resistors closer to a preferred value of zero.
    Type: Grant
    Filed: June 30, 2020
    Date of Patent: February 14, 2023
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventor: Mahalingam Nandakumar
  • Publication number: 20220375856
    Abstract: A method and an electronic device that includes an isolation structure having a dielectric material on or in a semiconductor surface layer, and a passive circuit component having a metal silicide structure on a side of the isolation structure, there the metal silicide structure includes a metal silicide portion and a dielectric portion, the dielectric portion of the metal silicide structure including one of silicon nitride, silicon oxide, silicon carbide, silicon carbon nitride, and silicon oxynitride. The method includes forming a dielectric material of the isolation structure on or in the semiconductor surface layer, forming a silicon-rich dielectric layer on a side of the isolation structure, and siliciding the silicon-rich dielectric layer to form the metal silicide structure on the side of the isolation structure.
    Type: Application
    Filed: September 30, 2021
    Publication date: November 24, 2022
    Applicant: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Yuguo Wang, Haowen Bu
  • Patent number: 11455452
    Abstract: The present disclosure provides a method for adjusting implant parameter conditions in semiconductor processing by wafer and by wafer zone using in-line measurements from previous operations and a feed-forward computer model. The feed-forward model is based on a sensitivity map of in-line measured data and its effect of electrical performance. Feed-forward computer models that adjust implant parameters by wafer and by zone improve both wafer-to-wafer and within wafer electrical uniformity in semiconductor devices.
    Type: Grant
    Filed: July 31, 2020
    Date of Patent: September 27, 2022
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Mahalingam Nandakumar, Murlidhar Bashyam, Alwin Tsao, Douglas Newman
  • Publication number: 20220208973
    Abstract: A semiconductor device including drain extended metal oxide semiconductor field effect transistor (MOSFET) includes a source region and a drain region each having a first dopant type spaced apart along a surface of a semiconductor material having a second opposite conductivity type. A gate electrode over the semiconductor material surface between the source region and the drain region. A diffusion suppression implant region in the semiconductor material extends from the source region under the gate electrode. The diffusion suppression implant region includes a body region having the second opposite conductivity type and comprises at least one of carbon, nitrogen, and fluorine.
    Type: Application
    Filed: January 24, 2021
    Publication date: June 30, 2022
    Applicant: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Alexei Sadovnikov, Henry Litzmann Edwards, Jarvis Benjamin Jacobs
  • Publication number: 20220209012
    Abstract: An integrated circuit is fabricated by forming transistors having gates of orthogonal orientations and implanting, at two first rotations, a first pocket implant using a first dopant type with a masking pattern on a substrate surface layer, the two first rotations respectively forming two first pocket implantation angles and two first pocket implantation beam orientations, and implanting, at two second rotations, a retrograde gate-edge diode leakage (GDL) reduction pocket implant using a second dopant type with the masking pattern on the substrate surface layer, the two second rotations respectively forming two GDL-reduction implantation angles and two GDL-reduction implantation beam orientations.
    Type: Application
    Filed: December 28, 2020
    Publication date: June 30, 2022
    Inventors: Brian Edward Hornung, Mahalingam Nandakumar
  • Publication number: 20220189954
    Abstract: The present disclosure provides a method for forming a semiconductor device containing MOS transistors both with and without source/drain extension regions in a semiconductor substrate having a semiconductor material on either side of a gate structure including a gate electrode on a gate dielectric formed in a semiconductor material. In devices with source/drain extensions, a diffusion suppression species of one or more of indium, carbon and a halogen are used. The diffusion suppression implant can be selectively provided only to the semiconductor devices with drain extensions while devices without drain extensions remain diffusion suppression implant free.
    Type: Application
    Filed: December 10, 2020
    Publication date: June 16, 2022
    Applicant: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Brian Edward Hornung
  • Publication number: 20220139907
    Abstract: A semiconductor device includes a resistor having a resistor body including polysilicon, with fluorine in the polysilicon. The resistor body has a laterally alternating distribution of silicon grain sizes. The semiconductor device further includes an MOS transistor having a gate including polysilicon with fluorine. The fluorine in the gate has a higher average concentration than the fluorine in the resistor body. The semiconductor device may be formed by forming a gate/resistor layer including polysilicon. A fluorine implant mask is formed over the gate/resistor layer, exposing the gate/resistor layer in an area for the gate and over implant segments in an area for the resistor body. The implant segments do not cover the entire area for the resistor body. Fluorine is implanted into the gate/resistor layer where exposed by the fluorine implant mask. The gate/resistor layer is patterned to form the gate and the resistor body.
    Type: Application
    Filed: November 1, 2020
    Publication date: May 5, 2022
    Applicant: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Yanbiao Pan
  • Publication number: 20220102553
    Abstract: A method for fabricating a transistor on a semiconductor wafer includes providing a partial transistor containing a gate stack, extension regions, and source/drain sidewalls. The method also includes performing a source/drain implant of the semiconductor wafer, forming a cap layer over the semiconductor wafer, and performing a source/drain anneal. In addition, the method includes performing a damage implant of the cap layer and removing the cap layer over the semiconductor wafer.
    Type: Application
    Filed: December 13, 2021
    Publication date: March 31, 2022
    Inventors: Mahalingam Nandakumar, Wayne Bather, Narendra Singh Mehta
  • Publication number: 20210408221
    Abstract: Methods and semiconductor circuits are described in which a polysilicon resistor body is formed over a semiconductor substrate. A first dopant species is implanted into the polysilicon resistor body at a first angle about parallel to a surface normal of a topmost surface of the polysilicon resistor body. A second dopant species is implanted into the polysilicon resistor body at a second angle greater than about 10° relative to the surface normal. The combination of implants reduces the different between the temperature coefficient (tempco) of resistance of narrow resistors relative to the tempco of wide resistors, and brings the tempco of the resistors closer to a preferred value of zero.
    Type: Application
    Filed: June 30, 2020
    Publication date: December 30, 2021
    Inventor: Mahalingam NANDAKUMAR
  • Patent number: 11205578
    Abstract: A method of fabricating an integrated circuit (IC) includes providing a substrate having a semiconductor surface layer thereon including a field dielectric in a portion of the semiconductor surface layer and a pair of matched devices in at least one of a CMOS area, BiCMOS area, bipolar transistor area, and a resistor area. Dopants are ion implanted into the at least one of the CMOS area, the BiCMOS area, the bipolar transistor area, and the resistor area. The substrate is annealed in a processing chamber of a rapid thermal processor (RTP). The annealing comprises an initial temperature stabilization step including first annealing at a lower temperature for a first time of at least 20 seconds, and then a second annealing comprising ramping from the lower temperature to a peak higher temperature that is at least 100° C. higher (>) than the lower temperature.
    Type: Grant
    Filed: October 16, 2018
    Date of Patent: December 21, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Brian K. Kirkpatrick, Kenneth Palomino, Mahalingam Nandakumar
  • Patent number: 11152350
    Abstract: An electronic device, e.g. integrated circuit, has an n-type region and a p-type region located within a semiconductor substrate, the n-type region and the p-type region each intersecting the substrate surface. A dielectric structure is located directly on the substrate surface. The dielectric structure has first and second laterally opposed sides, with the first side located over the n-type region and the second side located over the p-type region.
    Type: Grant
    Filed: December 14, 2018
    Date of Patent: October 19, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Mahalingam Nandakumar, Alan Erik Segervall, Muhammad Yusuf Ali
  • Publication number: 20210193467
    Abstract: In a described example, an integrated circuit (IC) includes a metal oxide semiconductor (MOS) transistor formed in a semiconductor substrate. The transistor includes a gate structure formed over a surface of the substrate and source and drain regions having a first conductivity type formed in the substrate on both sides of the gate structure. A well region having a second opposite conductivity type is between the source and drain regions under the gate structure. The well region includes a well dopant and a through-gate co-implant species. The well dopant and the co-implant species have a retrograde profile extending from the surface of the substrate into the well region.
    Type: Application
    Filed: December 11, 2020
    Publication date: June 24, 2021
    Inventors: MAHALINGAM NANDAKUMAR, BRIAN EDWARD HORNUNG, LI JEN CHOI
  • Patent number: 11011508
    Abstract: An electronic device, e.g. an integrated circuit, is formed on a P-type lightly-doped semiconductor substrate having an N-type buried layer. First and second N-wells extend from a surface of the substrate to the buried layer. A first NSD region is located within the first N-well, and a second NSD region is located within the second N-well. A PSD region extends from the substrate surface into the substrate and is located between the first and second NSD regions. A P-type lightly-doped portion of the substrate is located between the N-well and the substrate surface and between the PSD region and the first and second NSD regions.
    Type: Grant
    Filed: December 14, 2018
    Date of Patent: May 18, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Mahalingam Nandakumar, Robert Callaghan Taft, Alan Erik Segervall, Muhammad Yusuf Ali
  • Publication number: 20210125872
    Abstract: Fabrication of an integrated circuit includes forming a photoresist layer over a substrate. Target regions defined on the substrate are exposed using a reticle that defines a first exposure window for a first doped structure of a first type; the first exposure window has a first plurality of openings and a first plurality of dopant blocking regions. A respective exposure dose for each of the target regions is determined by an exposure map and provides controlled variations in the size of the first plurality of openings across the plurality of target regions. Subsequent to the exposure and to developing the photoresist, a dopant is implanted into the substrate through the first plurality of openings.
    Type: Application
    Filed: October 24, 2019
    Publication date: April 29, 2021
    Inventor: Mahalingam Nandakumar
  • Publication number: 20210089694
    Abstract: The present disclosure provides a method for adjusting implant parameter conditions in semiconductor processing by wafer and by wafer zone using in-line measurements from previous operations and a feed-forward computer model. The feed-forward model is based on a sensitivity map of in-line measured data and its effect of electrical performance. Feed-forward computer models that adjust implant parameters by wafer and by zone improve both wafer-to-wafer and within wafer electrical uniformity in semiconductor devices.
    Type: Application
    Filed: July 31, 2020
    Publication date: March 25, 2021
    Inventors: Mahalingam Nandakumar, Murlidhar Bashyam, Alwin Tsao, Douglas Newman
  • Publication number: 20200279905
    Abstract: An integrated circuit includes a polysilicon resistor having a plurality of segments, including first, second and third segments, the second segment located between and running about parallel to the first and third segments. A first header connects the first and second segments, and a second header connects the second and third segments. A first metal silicide layer located over the first header extends over the first and second segments toward the second header. A second metal silicide layer located over the second header extends over the second and third segments toward the first header. A dielectric layer is located over and contacts the first, second and third segments between the first and second metal silicide layers.
    Type: Application
    Filed: February 25, 2020
    Publication date: September 3, 2020
    Inventor: Mahalingam Nandakumar
  • Publication number: 20200194422
    Abstract: An electronic device, e.g. integrated circuit, has an n-type region and a p-type region located within a semiconductor substrate, the n-type region and the p-type region each intersecting the substrate surface. A dielectric structure is located directly on the substrate surface. The dielectric structure has first and second laterally opposed sides, with the first side located over the n-type region and the second side located over the p-type region.
    Type: Application
    Filed: December 14, 2018
    Publication date: June 18, 2020
    Inventors: Mahalingam Nandakumar, Alan Erik Segervall, Muhammad Yusuf Ali