Patents by Inventor Sundar Chetlur

Sundar Chetlur 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: 10566526
    Abstract: A method includes depositing on a substrate a magnetoresistance stack, depositing a first hard mask on the magnetoresistance stack, depositing a first photoresist on the first hard mask, patterning the first photoresist to expose portions of the first hard mask, and etching the exposed portions of the first hard mask to expose a portion of the magnetoresistance stack. The method further includes stripping the first photoresist, etching the exposed portions of the magnetoresistance stack and the first hard mask to form a first intermediate structure having a base and a pillar structure, depositing an etch barrier on the first intermediate structure, and depositing a second hard mask on the etch barrier. A second photoresist is deposited on the second hard mask.
    Type: Grant
    Filed: September 5, 2018
    Date of Patent: February 18, 2020
    Assignee: Allegro MicroSystems, LLC
    Inventors: Yen Ting Liu, Maxim Klebanov, Paolo Campiglio, Sundar Chetlur
  • Publication number: 20190363162
    Abstract: A metal-oxide semiconductor (MOS) transistor structure is provided herein having one or more horizontal and/or one or more vertical MOS transistor structures formed around trench and liner isolation regions. The trench region serves as a gate electrode, while the liner is formed around the sidewalls of trench region and serves as a gate dielectric of a parasitic MOS within the transistor structure. The MOS transistor structure includes various doped regions formed around one or more portions of the trench and liner regions. The doped regions can have one or more different doping types such that in response to a voltage applied to the trench region, a channel region is formed in at least one of the doped regions and provides a current path within the MOS transistor between different doped regions.
    Type: Application
    Filed: August 12, 2019
    Publication date: November 28, 2019
    Applicant: Allegro MicroSystems, LLC
    Inventors: Sundar Chetlur, Maxim Klebanov, Washington Lamar
  • Patent number: 10468485
    Abstract: A metal-oxide semiconductor (MOS) transistor structure is provided herein having one or more horizontal and/or one or more vertical MOS transistor structures formed around trench and liner isolation regions. The trench region serves as a gate electrode, while the liner is formed around the sidewalls of trench region and serves as a gate dielectric of a parasitic MOS within the transistor structure. The MOS transistor structure includes various doped regions formed around one or more portions of the trench and liner regions. The doped regions can have one or more different doping types such that in response to a voltage applied to the trench region, a channel region is formed in at least one of the doped regions and provides a current path within the MOS transistor between different doped regions.
    Type: Grant
    Filed: May 26, 2017
    Date of Patent: November 5, 2019
    Assignee: Allegro MicroSystems, LLC
    Inventors: Sundar Chetlur, Maxim Klebanov, Washington Lamar
  • Publication number: 20190285667
    Abstract: Systems and methods described herein are directed towards integrating a shield layer into a current sensor to shield a magnetic field sensing element and associated circuitry in the current sensor from electrical, voltage, or electrical transient noise. In an embodiment, a shield layer may be disposed along at least one surface of a die supporting a magnetic field sensing element. The shield layer may be disposed in various arrangements to shunt noise caused by a parasitic coupling between the magnetic field sensing element and the current carrying conductor away from the magnetic field sensing element.
    Type: Application
    Filed: May 24, 2019
    Publication date: September 19, 2019
    Applicant: Allegro MicroSystems, LLC
    Inventors: Shaun D. Milano, Bryan Cadugan, Michael C. Doogue, Alexander Latham, William P. Taylor, Harianto Wong, Sundar Chetlur
  • Patent number: 10352969
    Abstract: Systems and methods described herein are directed towards integrating a shield layer into a current sensor to shield a magnetic field sensing element and associated circuitry in the current sensor from electrical, voltage, or electrical transient noise. In an embodiment, a shield layer may be disposed along at least one surface of a die supporting a magnetic field sensing element. The shield layer may be disposed in various arrangements to shunt noise caused by a parasitic coupling between the magnetic field sensing element and the current carrying conductor away from the magnetic field sensing element.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: July 16, 2019
    Assignee: Allegro MicroSystems, LLC
    Inventors: Shaun D. Milano, Bryan Cadugan, Michael C. Doogue, Alexander Latham, William P. Taylor, Harianto Wong, Sundar Chetlur
  • Publication number: 20190067562
    Abstract: Methods and apparatus for a signal isolator having a dielectric interposer supporting first and second die each having a magnetic field sensing element. A first signal path extends from the first die to the second die and a second signal path extends from the second die to the first die. In embodiments, the first signal path is located in the interposer and includes a first coil to generate a magnetic field and the second signal path is located in the interposer and includes a second coil to generate a magnetic filed. The first coil is located in relation to the second magnetic field sensing element of the second die and the second coil is located in relation to the first magnetic field sensing element of the first die.
    Type: Application
    Filed: August 29, 2017
    Publication date: February 28, 2019
    Applicant: Allegro MicroSystems, LLC
    Inventors: Sundar Chetlur, Harianto Wong, Maxim Klebanov, William P. Taylor, Michael C. Doogue
  • Publication number: 20180342500
    Abstract: A metal-oxide semiconductor (MOS) transistor structure is provided herein having one or more horizontal and/or one or more vertical MOS transistor structures formed around trench and liner isolation regions. The trench region serves as a gate electrode, while the liner is formed around the sidewalls of trench region and serves as a gate dielectric of a parasitic MOS within the transistor structure. The MOS transistor structure includes various doped regions formed around one or more portions of the trench and liner regions. The doped regions can have one or more different doping types such that in response to a voltage applied to the trench region, a channel region is formed in at least one of the doped regions and provides a current path within the MOS transistor between different doped regions.
    Type: Application
    Filed: May 26, 2017
    Publication date: November 29, 2018
    Applicant: Allegro Microsystems, LLC
    Inventors: Sundar Chetlur, Maxim Klebanov, Washington Lamar
  • Publication number: 20180149677
    Abstract: Systems and methods described herein are directed towards integrating a shield layer into a current sensor to shield a magnetic field sensing element and associated circuitry in the current sensor from electrical, voltage, or electrical transient noise. In an embodiment, a shield layer may be disposed along at least one surface of a die supporting a magnetic field sensing element. The shield layer may be disposed in various arrangements to shunt noise caused by a parasitic coupling between the magnetic field sensing element and the current carrying conductor away from the magnetic field sensing element.
    Type: Application
    Filed: November 29, 2016
    Publication date: May 31, 2018
    Applicant: Allegro MicroSystems, LLC
    Inventors: Shaun D. Milano, Bryan Cadugan, Michael C. Doogue, Alexander Latham, William P. Taylor, Harianto Wong, Sundar Chetlur
  • Patent number: 9230861
    Abstract: A backside contact structure is created using the following sequence of steps: etching a deep trench from the front surface of the semiconductor wafer to the buried layer to be contacted; depositing an isolation layer into the trench which covers the surfaces of the trench; performing an ion beam anisotropic etch in order to selectively etch the isolation layer at the bottom of the trench; filling the trench with a conductive material in order to create an electrical connection to the backside layer. The process can either be performed at a front-end stage of wafer processing following the formation of shallow trench isolation structures, or at a back-end stage after device transistors are formed. The backside contact structure so fabricated is used to electrically isolate circuit structures constructed on the wafer's upper surface, so that the various components of an integrated circuit can operate at different reference voltages.
    Type: Grant
    Filed: October 9, 2013
    Date of Patent: January 5, 2016
    Assignee: Telefunken Semiconductors America LLC
    Inventors: Sundar Chetlur, Guy Ng
  • Publication number: 20140099772
    Abstract: A backside contact structure is created using the following sequence of steps: etching a deep tench from the front surface of the semiconductor wafer to the buried layer to be contacted; depositing an isolation layer into the trench which covers the surfaces of the trench; performing an ion beam anisotropic etch in order to selectively etch the isolation layer at the bottom of the trench; filling the trench with a conductive material in order to create an electrical connection to the backside layer. The process can either be performed at a front-end stage of wafer processing following the formation of shallow trench isolation structures, or at a back-end stage after device transistors are formed. The backside contact structure so fabricated is used to electrically isolate circuit structures constructed on the wafer's upper surface, so that the various components of an integrated circuit can operate at different reference voltages.
    Type: Application
    Filed: October 9, 2013
    Publication date: April 10, 2014
    Inventors: Sundar Chetlur, Guy Ng
  • Patent number: 6664800
    Abstract: A non-contact method for determining a quality of a semiconductor dielectric. The method includes depositing a charge on a dielectric to achieve a high voltage on the dielectric, measuring a voltage drop of the dielectric as a function of time, and determining a soft breakdown voltage of the dielectric from the voltage drop as a function of time. The amount of charge that is deposited may vary. For example, the charge may be deposited until a voltage that ranges from about 4 megavolts to about 16 megavolts is achieved on the dielectric. The amount of charge may also depend on the thickness of the dielectric. For example, applying a charge as a function of the thickness may include applying 4 megavolts when the thickness is about 1.2 nm or applying 16 megavolts when the thickness is about 5.0 nm.
    Type: Grant
    Filed: January 8, 2001
    Date of Patent: December 16, 2003
    Assignee: Agere Systems Inc.
    Inventors: Carlos M. Chacon, Sundar Chetlur, Pradip K. Roy
  • Patent number: 6605529
    Abstract: The present invention provides a method of manufacturing a semiconductor device that includes incorporation of a hydrogen isotope at a relatively high processing temperature during gate oxidation or polysilicon gate electrode deposition to maximize incorporation of hydrogen isotope at interfaces deliberately created during oxidation (such as graded oxidation) as multilayered poly/alpha-silicon deposition process.
    Type: Grant
    Filed: May 11, 2001
    Date of Patent: August 12, 2003
    Assignee: Agere Systems Inc.
    Inventors: Sundar Chetlur, Jennifer M. McKinley, Minesh A. Patel, Pradip K. Roy, Jonathan Zhong-Ning Zhou
  • Publication number: 20020168841
    Abstract: The present invention provides a method of manufacturing a semiconductor device that includes incorporation of a hydrogen isotope at a relatively high processing temperature during gate oxidation or polysilicon gate electrode deposition to maximize incorporation of hydrogen isotope at interfaces deliberately created during oxidation (such as graded oxidation) as multilayered poly/alpha-silicon deposition process.
    Type: Application
    Filed: May 11, 2001
    Publication date: November 14, 2002
    Inventors: Sundar Chetlur, Jennifer M. McKinley, Minesh A. Patel, Pradip K. Roy, Jonathan Zhong-Ning Zhou
  • Publication number: 20020121914
    Abstract: The present invention provides a non-contact method for determining a quality of a semiconductor dielectric. The method includes depositing a charge on a dielectric to achieve a high voltage on the dielectric, measuring a voltage drop of the dielectric as a function of time, and determining soft breakdown of the dielectric from the voltage drop as a function of time. The amount of charge that is deposited may vary. For example, the charge may be deposited until a voltage that ranges from about 4 megavolts to about 16 megavolts is achieved on the dielectric. The amount of charge may also depend on the thickness of the dielectric. For example, applying a charge as a function of the thickness may include applying 4 megavolts when the thickness is about 1.2 nm or applying 16 megavolts when the thickness is about 5.0 nm.
    Type: Application
    Filed: January 8, 2001
    Publication date: September 5, 2002
    Inventors: Carlos M. Chacon, Sundar Chetlur, Pradip K. Roy
  • Patent number: 6198301
    Abstract: The present invention provides a method for determining a hot carrier lifetime of a transistor. In one embodiment, the method comprises the steps of determining an initial transconductance (gm1) of a transistor, and then, applying a stress voltage, which does not exceed a maximum breakdown voltage of the transistor, to the transistor to cause a transconductance degradation of the transistor, and then determining a subsequent transconductance (gm2) of the transistor. A hot carrier lifetime of the transistor can then be determined as a function of gm1 and gm2. Thus, the present invention provides a method in which the hot carrier lifetime is determined from sequential transconductance measurements without intervening, transistor characteristic tests that are typically conducted between the transconductance measurements that degrade the sensitivity of the gm measurement.
    Type: Grant
    Filed: July 23, 1998
    Date of Patent: March 6, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Sundar Chetlur, Merlyne M. De Souza, Anthony S. Oates