Patents by Inventor Seetharaman Sridhar

Seetharaman Sridhar 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: 20240113217
    Abstract: An integrated circuit includes first and second trenches in a semiconductor substrate and a semiconductor mesa between the first and second trenches. A source region having a first conductivity type and a body region having an opposite second conductivity type are located within the semiconductor mesa. A trench shield is located within the first trench, and a gate electrode is over the trench shield between first and second sidewalls of the first trench. A gate dielectric is on a sidewall of the first trench between the gate electrode and the body region, and a pre-metal dielectric (PMD) layer is over the gate electrode. A gate contact through the PMD layer touches the gate electrode between the first and second sidewalls, and a trench shield contact through the PMD layer touches the trench shield between the first and second sidewalls.
    Type: Application
    Filed: September 30, 2022
    Publication date: April 4, 2024
    Inventors: Hong Yang, Thomas Grebs, Yunlong Liu, Sunglyong Kim, Lindong Li, Peng Li, Seetharaman Sridhar, Yeguang Zhang, Sheng pin Yang
  • Publication number: 20230395589
    Abstract: An electrostatic discharge (ESD) protection structure that provides snapback protections to one or more high voltage circuit components. The ESD protection structure can be integrated along a peripheral region of a high voltage circuit, such as a high side gate driver of a driver circuit. The ESD protection structure includes a bipolar transistor structure interfacing with a PN junction of a high voltage device, which is configured to discharge the ESD current during an ESD event. The bipolar transistor structure has a collector region overlapping the PN junction, a base region embedded with sufficient pinch resistance to launch the snapback protection, and an emitter region for discharging the ESD current.
    Type: Application
    Filed: August 17, 2023
    Publication date: December 7, 2023
    Inventors: Sunglyong Kim, David LaFonteese, Seetharaman Sridhar, Sameer Pendharkar
  • Patent number: 11791198
    Abstract: A semiconductor device has a semiconductor material in a substrate. The semiconductor device has an MOS transistor. A trench in the substrate extends from a top surface of the substrate) into the semiconductor material. A shield is disposed in the trench. The shield has a contact portion which extends toward a top surface of the trench. A gate of the MOS transistor is disposed in the trench over the shield. The gate is electrically isolated from the shield. The gate is electrically isolated from the contact portion of the shield by a shield isolation layer which covers an angled surface of the contact portion extending toward the top of the trench. Methods of forming the semiconductor device are disclosed.
    Type: Grant
    Filed: March 15, 2022
    Date of Patent: October 17, 2023
    Assignee: Texas Instruments Incorporated
    Inventors: Hong Yang, Seetharaman Sridhar, Ya ping Chen, Fei Ma, Yunlong Liu, Sunglyong Kim
  • Patent number: 11764208
    Abstract: An electrostatic discharge (ESD) protection structure that provides snapback protections to one or more high voltage circuit components. The ESD protection structure can be integrated along a peripheral region of a high voltage circuit, such as a high side gate driver of a driver circuit. The ESD protection structure includes a bipolar transistor structure interfacing with a PN junction of a high voltage device, which is configured to discharge the ESD current during an ESD event. The bipolar transistor structure has a collector region overlapping the PN junction, a base region embedded with sufficient pinch resistance to launch the snapback protection, and an emitter region for discharging the ESD current.
    Type: Grant
    Filed: December 16, 2020
    Date of Patent: September 19, 2023
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sunglyong Kim, David LaFonteese, Seetharaman Sridhar, Sameer Pendharkar
  • Publication number: 20230246107
    Abstract: An integrated circuit includes a trench gate MOSFET including MOSFET cells. Each MOSFET cell includes an active trench gate in an n-epitaxial layer oriented in a first direction with a polysilicon gate over a lower polysilicon portion. P-type body regions are between trench gates and are separated by an n-epitaxial region. N-type source regions are located over the p-type regions. A gate dielectric layer is between the polysilicon gates and the body regions. A metal-containing layer contacts the n-epitaxial region to provide an anode of an embedded Schottky diode. A dielectric layer over the n-epitaxial layer has metal contacts therethrough connecting to the n-type source regions, to the p-type body regions, and to the anode of the Schottky diode.
    Type: Application
    Filed: April 13, 2023
    Publication date: August 3, 2023
    Inventors: SUNGLYONG KIM, SEETHARAMAN SRIDHAR, HONG YANG, YA PING CHEN, THOMAS EUGENE GREBS
  • Patent number: 11658241
    Abstract: An integrated circuit includes a trench gate MOSFET including MOSFET cells. Each MOSFET cell includes an active trench gate in an n-epitaxial layer oriented in a first direction with a polysilicon gate over a lower polysilicon portion. P-type body regions are between trench gates and are separated by an n-epitaxial region. N-type source regions are located over the p-type regions. A gate dielectric layer is between the polysilicon gates and the body regions. A metal-containing layer contacts the n-epitaxial region to provide an anode of an embedded Schottky diode. A dielectric layer over the n-epitaxial layer has metal contacts therethrough connecting to the n-type source regions, to the p-type body regions, and to the anode of the Schottky diode.
    Type: Grant
    Filed: December 31, 2018
    Date of Patent: May 23, 2023
    Assignee: Texas Instruments Incorporated
    Inventors: Sunglyong Kim, Seetharaman Sridhar, Hong Yang, Ya Ping Chen, Thomas Eugene Grebs
  • Publication number: 20230132375
    Abstract: An electrostatic discharge (ESD) protection structure that provides snapback protections to one or more high voltage circuit components. The ESD protection structure can be integrated along a peripheral region of a high voltage circuit, such as a high side gate driver of a driver circuit. The ESD protection structure includes a bipolar transistor structure interfacing with a PN junction of a high voltage device, which is configured to discharge the ESD current during an ESD event. The bipolar transistor structure has a collector region overlapping the PN junction, a base region embedded with sufficient pinch resistance to launch the snapback protection, and an emitter region for discharging the ESD current.
    Type: Application
    Filed: December 16, 2020
    Publication date: April 27, 2023
    Inventors: Sunglyong Kim, David LaFonteese, Seetharaman Sridhar, Sameer Pendharkar
  • Publication number: 20230101610
    Abstract: An integrated circuit includes an epitaxial layer over a semiconductor substrate. The epitaxial layer has a first conductivity type and a top surface. First, second and third trenches are located in the epitaxial layer. The trenches respectively include first, second and third field plates. First and second body members are located within the epitaxial layer and have a different second conductivity type. The first body member is located between the first and second trenches, and the second body member is located between the second and third trenches. The first body member extends a first distance between the top surface and the substrate, and the second body member extends a lesser second distance between the top surface and the substrate.
    Type: Application
    Filed: September 30, 2021
    Publication date: March 30, 2023
    Inventors: Meng-Chia LEE, Sunglyong KIM, Seetharaman SRIDHAR, Sameer PENDHARKAR
  • Publication number: 20230061337
    Abstract: An integrated circuit, including a source region, a drain region, a channel region between the source region and the drain region, and a gate for inducing a conductive path through the channel region. The integrated circuit also includes structure, proximate a curved length of the gate, for inhibiting current flow along a portion of the channel region.
    Type: Application
    Filed: August 31, 2021
    Publication date: March 2, 2023
    Inventors: Jungwoo Joh, Sunglyong Kim, Seetharaman Sridhar, Sameer Pendharkar, James Craig Ondrusek, Srikanth Krishnan
  • Patent number: 11456381
    Abstract: Described examples include an integrated circuit having a semiconductor substrate. The integrated circuit has a transistor that includes a buried layer having within the substrate, the buried layer defining a drift region between the buried layer and the top surface and a body region in the substrate extending from the buried layer to the surface of the substrate. The transistor also having a source formed in the body region, a drain extending from the buried layer to the surface of the substrate, a drift well extending from the buried layer toward the top surface and extending from the body region to the drain, a drift surface layer located between the drift well and the top, and a gate proximate to the surface of the substrate at the body region.
    Type: Grant
    Filed: December 16, 2020
    Date of Patent: September 27, 2022
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Meng-Chia Lee, Sunglyong Kim, Seetharaman Sridhar, Sameer Pendharkar
  • Publication number: 20220223731
    Abstract: A semiconductor device includes first, second and third trenches formed in a semiconductor layer having a first conductivity type. Each trench includes a corresponding field plate and a corresponding gate over each field plate. A first body region having a second opposite conductivity type is between the first and second gates, and a second body region having the second conductivity type is located between the second and third gates. A first source region is located over the first body region and a second source region is located over the second body region, the first and second source regions having the first conductivity type. A first gate bus is conductively connected to the first gate and a second gate bus is conductively connected to the second gate, the first gate bus conductively isolated from the second gate bus.
    Type: Application
    Filed: January 13, 2021
    Publication date: July 14, 2022
    Inventors: Sunglyong KIM, Seetharaman SRIDHAR, Meng-Chia LEE, Thomas Eugene GREBS, Hong YANG
  • Publication number: 20220208601
    Abstract: A semiconductor device has a semiconductor material in a substrate. The semiconductor device has an MOS transistor. A trench in the substrate extends from a top surface of the substrate) into the semiconductor material. A shield is disposed in the trench. The shield has a contact portion which extends toward a top surface of the trench. A gate of the MOS transistor is disposed in the trench over the shield. The gate is electrically isolated from the shield. The gate is electrically isolated from the contact portion of the shield by a shield isolation layer which covers an angled surface of the contact portion extending toward the top of the trench. Methods of forming the semiconductor device are disclosed.
    Type: Application
    Filed: March 15, 2022
    Publication date: June 30, 2022
    Inventors: Hong YANG, Seetharaman SRIDHAR, Ya ping CHEN, Fei MA, Yunlong LIU, Sunglyong KIM
  • Publication number: 20220190158
    Abstract: Described examples include an integrated circuit having a semiconductor substrate. The integrated circuit has a transistor that includes a buried layer having within the substrate, the buried layer defining a drift region between the buried layer and the top surface and a body region in the substrate extending from the buried layer to the surface of the substrate. The transistor also having a source formed in the body region, a drain extending from the buried layer to the surface of the substrate, a drift well extending from the buried layer toward the top surface and extending from the body region to the drain, a drift surface layer located between the drift well and the top, and a gate proximate to the surface of the substrate at the body region.
    Type: Application
    Filed: December 16, 2020
    Publication date: June 16, 2022
    Inventors: Meng-Chia Lee, Sunglyong Kim, Seetharaman Sridhar, Sameer Pendharkar
  • Patent number: 11322594
    Abstract: A semiconductor device, and methods of forming the same. In one example, the semiconductor device includes a trench in a substrate having a top surface, and a shield within the trench. The semiconductor device also includes a shield liner between a sidewall of the trench and the shield, and a lateral insulator over the shield contacting the shield liner. The semiconductor device also includes a gate dielectric layer on an exposed sidewall of the trench between the lateral insulator and the top surface. The lateral insulator may have a minimum thickness at least two times thicker than a maximum thickness of the gate dielectric layer.
    Type: Grant
    Filed: December 28, 2020
    Date of Patent: May 3, 2022
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Fei Ma, Ya ping Chen, Yunlong Liu, Hong Yang, Shengpin Yang, Baoqiang Niu, Rui Liu, Zhi Peng Feng, Seetharaman Sridhar, Sunglyong Kim
  • Patent number: 11322610
    Abstract: A device includes a laterally diffused MOSFET, which in turn includes n-type source and drain regions in a p-type semiconductor substrate. A gate electrode is located over the semiconductor substrate between the source region and the drain region. An isolation region is laterally spaced apart from the source region, and is bounded by an n-type buried layer and an n-type well region that reaches from a surface of the substrate to the buried layer. A p-type doped region and an n-type doped region are disposed within the isolation region, the p-type doped region and the n-type doped region forming a diode. A first conductive path connects the n-type doped region to the source region, and a second conductive path connects the p-type doped region to the gate electrode.
    Type: Grant
    Filed: January 30, 2020
    Date of Patent: May 3, 2022
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sunglyong Kim, Seetharaman Sridhar, Sameer Pendharkar
  • Patent number: 11302568
    Abstract: A semiconductor device has a semiconductor material in a substrate. The semiconductor device has an MOS transistor. A trench in the substrate extends from a top surface of the substrate) into the semiconductor material. A shield is disposed in the trench. The shield has a contact portion which extends toward a top surface of the trench. A gate of the MOS transistor is disposed in the trench over the shield. The gate is electrically isolated from the shield. The gate is electrically isolated from the contact portion of the shield by a shield isolation layer which covers an angled surface of the contact portion extending toward the top of the trench. Methods of forming the semiconductor device are disclosed.
    Type: Grant
    Filed: August 21, 2019
    Date of Patent: April 12, 2022
    Assignee: Texas Instruments Incorporated
    Inventors: Hong Yang, Seetharaman Sridhar, Ya ping Chen, Fei Ma, Yunlong Liu, Sunglyong Kim
  • Publication number: 20220052165
    Abstract: A semiconductor device, and methods of forming the same. In one example, the semiconductor device includes a trench in a substrate having a top surface, and a shield within the trench. The semiconductor device also includes a shield liner between a sidewall of the trench and the shield, and a lateral insulator over the shield contacting the shield liner. The semiconductor device also includes a gate dielectric layer on an exposed sidewall of the trench between the lateral insulator and the top surface. The lateral insulator may have a minimum thickness at least two times thicker than a maximum thickness of the gate dielectric layer.
    Type: Application
    Filed: December 28, 2020
    Publication date: February 17, 2022
    Inventors: Fei Ma, Ya ping Chen, Yunlong Liu, Hong Yang, Shengpin Yang, Baoqiang Niu, Rui Liu, Zhi Peng Feng, Seetharaman Sridhar, Sunglyong Kim
  • Patent number: 11239318
    Abstract: A semiconductor device includes a MOS transistor located within a semiconductor substrate of a first conductivity type. The transistor includes a body well located between a drain well and a substrate contact well. A buried voltage blocking region of a second conductivity type is located within the substrate and is connected to the body well. The buried voltage blocking region extends toward the substrate contact well, with an unmodified portion of the substrate remaining between the voltage blocking region and the substrate contact well.
    Type: Grant
    Filed: April 13, 2020
    Date of Patent: February 1, 2022
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sunglyong Kim, Seetharaman Sridhar, Sameer Pendharkar
  • Patent number: 11195915
    Abstract: In some examples, a semiconductor device, comprises a semiconductor substrate; an epitaxial layer having a top side disposed on the semiconductor substrate, wherein the epitaxial layer has a source implant region, a drain implant region, a first doped region, and a second doped region, wherein the first doped region is adjacent to the source implant region and the second doped region is adjacent to the drain implant region, wherein the top side has a sloped surface over the second doped region; a gate electrode supported by the top side; a source electrode in contact with the source implant region; and a drain electrode in contact with the drain implant region.
    Type: Grant
    Filed: April 15, 2019
    Date of Patent: December 7, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Haian Lin, Frank Alexander Baiocchi, Seetharaman Sridhar
  • Patent number: 11127852
    Abstract: A trench gate metal oxide semiconductor field effect transistor (MOSFET) device includes an epitaxial layer on a substrate both doped a first conductivity type. Active area trenches have polysilicon gates over a double shield field plate. A junction termination trench includes a single shield field plate in a junction termination area which encloses the active area that includes a retrograde dopant profile of the second conductivity type into the epitaxial layer in the junction termination area. Pbody regions of a second conductivity type are between active trenches and between the outermost active trench and the junction termination trench. Source regions of the first conductivity type are in the body regions between adjacent active trenches. Metal contacts are over contact apertures that extend through a pre-metal dielectric layer reaching the body region under the source region, the single shield field plate, and that couples together the polysilicon gates.
    Type: Grant
    Filed: December 27, 2018
    Date of Patent: September 21, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sunglyong Kim, Seetharaman Sridhar, Hong Yang, Ya Ping Chen, Yunlong Liu, Fei Ma