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).

  • Patent number: 8962406
    Abstract: An integrated circuit includes MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. An integrated circuit includes MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel.
    Type: Grant
    Filed: September 26, 2014
    Date of Patent: February 24, 2015
    Assignee: Texas Instruments Incorporated
    Inventor: Mahalingam Nandakumar
  • Patent number: 8941181
    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: December 10, 2012
    Date of Patent: January 27, 2015
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Sunitha Venkataraman, David L. Catlett, Jr.
  • Publication number: 20150008523
    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: Application
    Filed: September 26, 2014
    Publication date: January 8, 2015
    Inventors: Mahalingam Nandakumar, Sunitha Venkataraman, David L. Catlett, JR.
  • Publication number: 20150008518
    Abstract: An integrated circuit includes MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. An integrated circuit includes MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel.
    Type: Application
    Filed: September 26, 2014
    Publication date: January 8, 2015
    Inventor: Mahalingam NANDAKUMAR
  • Publication number: 20150008538
    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: Application
    Filed: July 2, 2013
    Publication date: January 8, 2015
    Inventor: Mahalingam NANDAKUMAR
  • Publication number: 20150011067
    Abstract: An integrated circuit includes MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. An integrated circuit includes MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel.
    Type: Application
    Filed: September 26, 2014
    Publication date: January 8, 2015
    Inventor: Mahalingam NANDAKUMAR
  • Patent number: 8927385
    Abstract: An integrated circuit having a replacement gate MOS transistor and a polysilicon resistor may be formed by removing a portion at the top surface of the polysilicon layer in the resistor area. A subsequently formed gate etch hard mask includes a MOS hard mask segment over a MOS sacrificial gate and a resistor hard mask segment over a resistor body. The resistor body is thinner than the MOS sacrificial gate. During the gate replacement process sequence, the MOS hard mask segment is removed, exposing the MOS sacrificial gate while at least a portion of the resistor hard mask segment remains over the resistor body. The MOS sacrificial gate is replaced by a replacement gate while the resistor body is not replaced.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: January 6, 2015
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Deborah J. Riley, Amitabh Jain
  • Patent number: 8878310
    Abstract: An integrated circuit with MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. An integrated circuit with MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and DEMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the DEMOS transistor gate overlying the DEMOS transistor channel. A method of forming an integrated circuit with MOS and LDMOS transistors with at least one of indium, carbon, nitrogen, and a halogen dopant raising the threshold voltage of a portion of the LDMOS transistor gate overlying the DEMOS transistor channel.
    Type: Grant
    Filed: January 21, 2013
    Date of Patent: November 4, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Mahalingam Nandakumar
  • Patent number: 8865557
    Abstract: In an embodiment of the invention, a method of forming an NMOS (n-type metal-oxide semiconductor) transistor is disclosed. A dual mask pattern is used to ion-implant source/drain regions of the NMOS transistor. The first mask allows first doses of As (arsenic), P (phosphorous) and N (Nitrogen) to be ion-implanted. After these doses are ion-implanted, a high temperature (900-1050 C) spike anneal is performed to activate the formed source/drains. A second mask allows a second dose of phosphorus to be implanted in the source/drain regions. The second dose of the phosphorus is typically higher than the first dose of phosphorus. The second dose of phosphorus lowers the Rsd (resistance of the source and drain regions) and dopes n-type poly-silicon blocks.
    Type: Grant
    Filed: August 12, 2014
    Date of Patent: October 21, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Mahalingam Nandakumar
  • Patent number: 8859377
    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: Grant
    Filed: June 29, 2007
    Date of Patent: October 14, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Wayne Bather, Narendra Singh Mehta
  • Patent number: 8853042
    Abstract: A method of forming an integrated circuit (IC) including a core and a non-core PMOS transistor includes forming a non-core gate structure including a gate electrode on a gate dielectric and a core gate structure including a gate electrode on a gate dielectric. The gate dielectric for the non-core gate structure is at least 2 ? of equivalent oxide thickness (EOT) thicker as compared to the gate dielectric for the core gate structure. P-type lightly doped drain (PLDD) implantation including boron establishes source/drain extension regions in the substrate. The PLDD implantation includes selective co-implanting of carbon and nitrogen into the source/drain extension region of the non-core gate structure. Source and drain implantation forms source/drain regions for the non-core and core gate structure, wherein the source/drain regions are distanced from the non-core and core gate structures further than their source/drain extension regions. Source/drain annealing is performed after source and drain implantation.
    Type: Grant
    Filed: January 7, 2014
    Date of Patent: October 7, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Amitabh Jain
  • Publication number: 20140264623
    Abstract: A method of fabricating a CMOS integrated circuit (IC) includes implanting a first n-type dopant at a first masking level that exposes a p-region of a substrate surface having a first gate stack thereon to form NLDD regions for forming n-source/drain extension regions for at least a portion of a plurality of n-channel MOS (NMOS) transistors on the IC. A p-type dopant is implanted at a second masking level that exposes an n-region in the substrate surface having a second gate stack thereon to form PLDD regions for at least a portion of a plurality of p-channel MOS (PMOS) transistors on the IC. A second n-type dopant is retrograde implanted including through the first gate stack to form a deep nwell (DNwell) for the portion of NMOS transistors. A depth of the DNwell is shallower below the first gate stack as compared to under the NLDD regions.
    Type: Application
    Filed: March 14, 2013
    Publication date: September 18, 2014
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventor: MAHALINGAM NANDAKUMAR
  • Patent number: 8835270
    Abstract: In an embodiment of the invention, a method of forming an NMOS (n-type metal-oxide semiconductor) transistor is disclosed. A dual mask pattern is used to ion-implant source/drain regions of the NMOS transistor. The first mask allows first doses of As (arsenic), P (phosphorous) and N (Nitrogen) to be ion-implanted. After these doses are ion-implanted, a high temperature (900-1050 C) spike anneal is performed to activate the formed source/drains. A second mask allows a second dose of phosphorus to be implanted in the source/drain regions. The second dose of the phosphorus is typically higher than the first dose of phosphorus. The second dose of phosphorus lowers the Rsd (resistance of the source and drain regions) and dopes n-type poly-silicon blocks.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: September 16, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Mahalingam Nandakumar
  • Publication number: 20140167182
    Abstract: An integrated circuit having a replacement gate MOS transistor and a polysilicon resistor may be formed by removing a portion at the top surface of the polysilicon layer in the resistor area. A subsequently formed gate etch hard mask includes a MOS hard mask segment over a MOS sacrificial gate and a resistor hard mask segment over a resistor body. The resistor body is thinner than the MOS sacrificial gate. During the gate replacement process sequence, the MOS hard mask segment is removed, exposing the MOS sacrificial gate while at least a portion of the resistor hard mask segment remains over the resistor body. The MOS sacrificial gate is replaced by a replacement gate while the resistor body is not replaced.
    Type: Application
    Filed: December 17, 2012
    Publication date: June 19, 2014
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Mahalingam Nandakumar, Deborah J. Riley, Amitabh Jain
  • Patent number: 8753944
    Abstract: A method of fabricating a Metal-Oxide Semiconductor (MOS) transistor includes providing a substrate having a substrate surface doped with a second dopant type and a gate stack over the substrate surface, and a masking pattern on the substrate surface which exposes a portion of the substrate surface for ion implantation. A first pocket implantation uses the second dopant type with the masking pattern on the substrate surface. At least one retrograde gate edge diode leakage (GDL) reduction pocket implantation uses the first dopant type with the masking pattern on the substrate surface. The first pocket implant and retrograde GDL reduction pocket implant are annealed. After annealing, the first pocket implant provides first pocket regions and the retrograde GDL reduction pocket implant provides an overlap with the first pocket regions to form a first counterdoped pocket portion within the first pocket regions.
    Type: Grant
    Filed: February 14, 2013
    Date of Patent: June 17, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Brian Hornung, Terry James Bordelon, Jr., Amitava Chatterjee
  • Publication number: 20140120675
    Abstract: A method of forming an integrated circuit (IC) including a core and a non-core PMOS transistor includes forming a non-core gate structure including a gate electrode on a gate dielectric and a core gate structure including a gate electrode on a gate dielectric. The gate dielectric for the non-core gate structure is at least 2 ? of equivalent oxide thickness (EOT) thicker as compared to the gate dielectric for the core gate structure. P-type lightly doped drain (PLDD) implantation including boron establishes source/drain extension regions in the substrate. The PLDD implantation includes selective co-implanting of carbon and nitrogen into the source/drain extension region of the non-core gate structure. Source and drain implantation forms source/drain regions for the non-core and core gate structure, wherein the source/drain regions are distanced from the non-core and core gate structures further than their source/drain extension regions. Source/drain annealing is performed after source and drain implantation.
    Type: Application
    Filed: January 7, 2014
    Publication date: May 1, 2014
    Applicant: Texas Instruments Incorporated
    Inventors: Mahalingam NANDAKUMAR, Amitabh JAIN
  • Patent number: 8659112
    Abstract: A method of forming an integrated circuit (IC) including a core and a non-core PMOS transistor includes forming a non-core gate structure including a gate electrode on a gate dielectric and a core gate structure including a gate electrode on a gate dielectric. The gate dielectric for the non-core gate structure is at least 2 ? of equivalent oxide thickness (EOT) thicker as compared to the gate dielectric for the core gate structure. P-type lightly doped drain (PLDD) implantation including boron establishes source/drain extension regions in the substrate. The PLDD implantation includes selective co-implanting of carbon and nitrogen into the source/drain extension region of the non-core gate structure. Source and drain implantation forms source/drain regions for the non-core and core gate structure, wherein the source/drain regions are distanced from the non-core and core gate structures further than their source/drain extension regions. Source/drain annealing is performed after source and drain implantation.
    Type: Grant
    Filed: December 14, 2010
    Date of Patent: February 25, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Amitabh Jain
  • Publication number: 20140021545
    Abstract: A method of fabricating a Metal-Oxide Semiconductor (MOS) transistor includes providing a substrate having a substrate surface doped with a second dopant type and a gate stack over the substrate surface, and a masking pattern on the substrate surface which exposes a portion of the substrate surface for ion implantation. A first pocket implantation uses the second dopant type with the masking pattern on the substrate surface. At least one retrograde gate edge diode leakage (GDL) reduction pocket implantation uses the first dopant type with the masking pattern on the substrate surface. The first pocket implant and retrograde GDL reduction pocket implant are annealed. After annealing, the first pocket implant provides first pocket regions and the retrograde GDL reduction pocket implant provides an overlap with the first pocket regions to form a first counterdoped pocket portion within the first pocket regions.
    Type: Application
    Filed: February 14, 2013
    Publication date: January 23, 2014
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: MAHALINGAM NANDAKUMAR, BRIAN HORNUNG, TERRY JAMES BORDELON, JR., AMITAVA CHATTERJEE
  • Publication number: 20140017869
    Abstract: A method of forming an integrated circuit (IC) having at least one PMOS transistor includes performing PLDD implantation including co-implanting indium, carbon and a halogen, and a boron specie to establish source/drain extension regions in a substrate having a semiconductor surface on either side of a gate structure including a gate electrode on a gate dielectric formed on the semiconductor surface. Source and drain implantation is performed to establish source/drain regions, wherein the source/drain regions are distanced from the gate structure further than the source/drain extension regions. Source/drain annealing is performed after the source and drain implantation. The co-implants can be selectively provided to only core PMOS transistors, and the method can include a ultra high temperature anneal such as a laser anneal after the PLDD implantation.
    Type: Application
    Filed: September 13, 2013
    Publication date: January 16, 2014
    Applicant: Texas Instruments Incorporated
    Inventors: Mahalingam NANDAKUMAR, Amitabh JAIN
  • Patent number: 8558310
    Abstract: A method of forming an integrated circuit (IC) having at least one PMOS transistor includes performing PLDD implantation including co-implanting indium, carbon and a halogen, and a boron specie to establish source/drain extension regions in a substrate having a semiconductor surface on either side of a gate structure including a gate electrode on a gate dielectric formed on the semiconductor surface. Source and drain implantation is performed to establish source/drain regions, wherein the source/drain regions are distanced from the gate structure further than the source/drain extension regions. Source/drain annealing is performed after the source and drain implantation. The co-implants can be selectively provided to only core PMOS transistors, and the method can include a ultra high temperature anneal such as a laser anneal after the PLDD implantation.
    Type: Grant
    Filed: December 14, 2010
    Date of Patent: October 15, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Mahalingam Nandakumar, Amitabh Jain