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: 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
  • Publication number: 20200194423
    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: Application
    Filed: December 14, 2018
    Publication date: June 18, 2020
    Inventors: Mahalingam Nandakumar, Robert Callaghan Taft, Alan Erik Segervall, Muhammad Yusuf Ali
  • Patent number: 10593680
    Abstract: An integrated circuit contains a logic MOS transistor and a memory MOS transistor of a same polarity. The logic MOS transistor has a logic channel stop layer. The memory MOS transistor has a memory channel stop layer. An average dopant density of the memory channel stop layer is higher than an average dopant density of the logic channel stop layer. The integrated circuit is formed by forming a global mask which exposes both the logic and memory MOS transistors. A global channel stop dose of dopants is implanted in the logic and memory MOS transistors. A memory mask is formed which exposes the memory MOS transistor and covers the logic MOS transistor. A memory channel stop dose of dopants of the same polarity is implanted into the memory MOS transistors. The memory channel stop dose of dopants is blocked from the logic MOS transistors.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: March 17, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventor: Mahalingam Nandakumar
  • Patent number: 10497695
    Abstract: An integrated circuit with a shallow trench isolated, low capacitance, ESD protection diode. An integrated circuit with a gate space isolated, low capacitance, ESD protection diode. An integrated circuit with a gate space isolated, low capacitance, ESD protection diode in parallel with a shallow trench isolated, low capacitance, ESD protection diode.
    Type: Grant
    Filed: January 24, 2017
    Date of Patent: December 3, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Mahalingam Nandakumar, Sunitha Venkataraman, David L. Catlett, Jr.
  • Patent number: 10439041
    Abstract: A replacement metal gate transistor structure and method with thin silicon nitride sidewalls and with little or no high-k dielectric on the vertical sidewalls of the replacement gate transistor trench.
    Type: Grant
    Filed: August 25, 2017
    Date of Patent: October 8, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Hiroaki Niimi, Mahalingam Nandakumar
  • Patent number: 10276684
    Abstract: An integrated circuit may include a metal gate which extends over an active area and onto an isolation dielectric layer. A conductive spline is formed on the metal gate, extending on the metal gate over at least a portion of the isolation dielectric layer, and extending on the metal gate for a length at least four times a width of the metal gate.
    Type: Grant
    Filed: December 8, 2016
    Date of Patent: April 30, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Mahalingam Nandakumar, Steve Lytle
  • Publication number: 20190115226
    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: Application
    Filed: October 16, 2018
    Publication date: April 18, 2019
    Inventors: BRIAN K. KIRKPATRICK, KENNETH PALOMINO, MAHALINGAM NANDAKUMAR
  • Patent number: 10249621
    Abstract: A method of limiting plasma charging damage on ICs. A die includes gate stacks on active areas defined by a field dielectric. A pre-metal dielectric (PMD) layer is over the gate electrode. A contact masking material pattern is defined on the PMD layer including first contact defining features for forming active contacts and second contact defining features for forming dummy contacts (DC's) including over active areas and gate electrodes. Contacts are etched through the PMD layer using the contact masking material pattern to form active contacts and DC's. A patterned metal 1 (M1) layer is formed including first M1 portions over the active contacts and dummy M1 portions over the DC's. Metallization processing follows including forming interconnects so that the active contacts are connected to MOS transistors on the IC, and the DC's are not electrically connected to the MOS transistors.
    Type: Grant
    Filed: December 15, 2016
    Date of Patent: April 2, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Mark Robert Visokay, Tae S. Kim, Mahalingam Nandakumar, Eric D. Rullan, Gregory B. Shinn
  • Patent number: 10115638
    Abstract: An integrated circuit containing MOS transistors with replacement gates may be formed with elevated LDD regions and/or recessed replacement gates on a portion of the transistors. Elevating the LDD regions is accomplished by a selective epitaxial process prior to LDD implant. Recessing the replacement gates is accomplished by etching substrate material after removal of sacrificial gate material and before formation of a replacement gate dielectric layer. Elevating the LDD regions and recessing the replacement gates may increase a channel length of the MOS transistors and thereby desirably increase threshold uniformity of the transistors.
    Type: Grant
    Filed: June 6, 2016
    Date of Patent: October 30, 2018
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventor: Mahalingam Nandakumar