Patents by Inventor Sandeep Bahl

Sandeep Bahl 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: 20240047529
    Abstract: GaN devices with a modified heterojunction structure and methods of making thereof are described. The GaN device comprises a heterojunction structure modified to include one or more deactivated regions. The heterojunction structure of the deactivated regions has different structural configurations than that of the as-grown heterojunction structure. The locally confined structural alteration of the heterojunction structure weakens or prohibits 2DEG formation in the deactivated regions. Moreover, the amount of net charges mapped to a field plate positioned above the heterojunction structure can be locally reduced or eliminated. Consequently, the electric field present between the heterojunction structure and the field plate can be reduced.
    Type: Application
    Filed: August 31, 2022
    Publication date: February 8, 2024
    Inventors: DONG SEUP LEE, CHANG SOO SUH, YOGANAND SARIPALLI, MENG-CHIA LEE, JUNGWOO JOH, JAMES TEHERANI, SANDEEP BAHL
  • Patent number: 8735980
    Abstract: A semiconductor structure, which serves as the core of a semiconductor fabrication platform, has a combination of empty-well regions and filled-well regions variously used by electronic elements, particularly insulated-gate field-effect transistors (“IGFETs”), to achieve desired electronic characteristics. A relatively small amount of semiconductor well dopant is near the top of an empty well. A considerable amount of semiconductor well dopant is near the top of a filled well. Some IGFETs (100, 102, 112, 114, 124, and 126) utilize empty wells (180, 182, 192, 194, 204, and 206) in achieving desired transistor characteristics. Other IGFETs (108, 110, 116, 118, 120, and 122) utilize filled wells (188, 190, 196, 198, 200, and 202) in achieving desired transistor characteristics.
    Type: Grant
    Filed: November 6, 2012
    Date of Patent: May 27, 2014
    Assignee: National Semiconductor Corporation
    Inventors: Constantin Bulucea, Sandeep Bahl, William French, Jeng-Jiun Yang, Donald Archer, David C. Parker, Prasad Chaparala
  • Patent number: 8723226
    Abstract: An enhancement-mode group III-N high electron mobility transistor (HEMT) with a reverse polarization cap is formed in a method that utilizes a reverse polarization cap structure, such as an InGaN cap structure, to deplete the two-dimensional electron gas (2DEG) and form a normally off device, and a spacer layer that lies below the reverse polarization cap structure and above the barrier layer of the HEMT which allows the reverse polarization cap layer to be etched without etching into the barrier layer.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: May 13, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Sandeep Bahl
  • Patent number: 8513703
    Abstract: The Si substrate of a group III-N HEMT is formed in layers that define a p-n junction which electrically isolates an upper region of the Si substrate from a lower region of the Si substrate. As a result, the upper region of the Si substrate can electrically float, thereby obtaining a full buffer breakdown voltage, while the lower region of the Si substrate can be attached to a package by way of a conductive epoxy, thereby significantly improving the thermal conductivity of the group III-N HEMT and minimizing undesirable floating-voltage regions.
    Type: Grant
    Filed: October 20, 2010
    Date of Patent: August 20, 2013
    Assignee: National Semiconductor Corporation
    Inventors: Sandeep Bahl, Constantin Bulucea
  • Patent number: 8502273
    Abstract: The buffer breakdown of a group III-N HEMT on a p-type Si substrate is significantly increased by forming an n-well in the p-type Si substrate to lie directly below the metal drain region of the group III-N HEMT. The n-well forms a p-n junction which becomes reverse biased during breakdown, thereby increasing the buffer breakdown by the reverse-biased breakdown voltage of the p-n junction and allowing the substrate to be grounded. The buffer layer of a group III-N HEMT can also be implanted with n-type and p-type dopants which are aligned with the p-n junction to minimize any leakage currents at the junction between the substrate and the buffer layer.
    Type: Grant
    Filed: October 20, 2010
    Date of Patent: August 6, 2013
    Assignee: National Semiconductor Corporation
    Inventors: Sandeep Bahl, Constantin Bulucea
  • Publication number: 20130126889
    Abstract: An enhancement-mode group III-N high electron mobility transistor (HEMT) with a reverse polarization cap is formed in a method that utilizes a reverse polarization cap structure, such as an InGaN cap structure, to deplete the two-dimensional electron gas (2DEG) and form a normally off device, and a spacer layer that lies below the reverse polarization cap structure and above the barrier layer of the HEMT which allows the reverse polarization cap layer to be etched without etching into the barrier layer.
    Type: Application
    Filed: November 22, 2011
    Publication date: May 23, 2013
    Inventor: Sandeep Bahl
  • Publication number: 20120139013
    Abstract: A static induction transistor comprising: a region of semiconductor material having a first conductivity type; at least two spaced-apart gate regions formed in the region of semiconductor material, the gate regions having a second conductivity type that is opposite to the first conductivity type; at least one source region having the first conductivity type formed in the region of semiconductor material between the spaced-apart gate regions; a drain region having the first conductivity type formed in the region of semiconductor and spaced-apart from the source region to define a channel region therebetween; and a dielectric carrier separation layer formed at the periphery of the gate regions.
    Type: Application
    Filed: December 3, 2010
    Publication date: June 7, 2012
    Inventors: Sandeep Bahl, Constantin Bulucea
  • Publication number: 20120098036
    Abstract: The Si substrate of a group III-N HEMT is formed in layers that define a p-n junction which electrically isolates an upper region of the Si substrate from a lower region of the Si substrate. As a result, the upper region of the Si substrate can electrically float, thereby obtaining a full buffer breakdown voltage, while the lower region of the Si substrate can be attached to a package by way of a conductive epoxy, thereby significantly improving the thermal conductivity of the group III-N HEMT and minimizing undesirable floating-voltage regions.
    Type: Application
    Filed: October 20, 2010
    Publication date: April 26, 2012
    Inventors: Sandeep Bahl, Constantin Bulucea
  • Publication number: 20120098035
    Abstract: The buffer breakdown of a group III-N HEMT on a p-type Si substrate is significantly increased by forming an n-well in the p-type Si substrate to lie directly below the metal drain region of the group III-N HEMT. The n-well forms a p-n junction which becomes reverse biased during breakdown, thereby increasing the buffer breakdown by the reverse-biased breakdown voltage of the p-n junction and allowing the substrate to be grounded. The buffer layer of a group III-N HEMT can also be implanted with n-type and p-type dopants which are aligned with the p-n junction to minimize any leakage currents at the junction between the substrate and the buffer layer.
    Type: Application
    Filed: October 20, 2010
    Publication date: April 26, 2012
    Inventors: Sandeep Bahl, Constantin Bulucea
  • Publication number: 20080079045
    Abstract: CMOS image sensor having high sensitivity and low crosstalk, particularly at far-red to infrared wavelengths, and a method for fabricating a CMOS image sensor. A CMOS image sensor has a substrate, an epitaxial layer above the substrate, and a plurality of pixels extending into the epitaxial layer for receiving light. The image sensor also includes at least one of a horizontal barrier layer between the substrate and the epitaxial layer for preventing carriers generated in the substrate from moving to the epitaxial layer, and a plurality of lateral barrier layers between adjacent ones of the plurality of pixels for preventing lateral diffusion of electrons in the epitaxial layer.
    Type: Application
    Filed: November 15, 2007
    Publication date: April 3, 2008
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Sandeep Bahl, Fredrick LaMaster, David Bigelow
  • Publication number: 20070052049
    Abstract: An integrated opto-electric sensor includes a wavenumber matching structure that is integrated onto a silicon substrate, and a first conductive electrode that is adjacent to one of a lightly doped and an undoped region in the silicon substrate to form a Schottky junction. A dielectric is positioned adjacent to the first conductive electrode, and a second conductive electrode is formed at the silicon substrate. The first conductive electrode and the second conductive electrode provide coupling for a detected signal that is provided in response to illumination of the wavenumber matching structure by an optical signal.
    Type: Application
    Filed: September 7, 2005
    Publication date: March 8, 2007
    Inventors: Sandeep Bahl, Daniel Roitman
  • Publication number: 20070037362
    Abstract: Method and apparatus for fabricating semiconductor devices, for example, III-V semiconductor devices, having a desired substrate, for example, a silicon substrate. A method for fabricating semiconductor devices includes providing a semiconductor wafer that includes a plurality of semiconductor structures attached to a native substrate formed of a first substrate material, and a host substrate formed of a second substrate material. At least one subset of semiconductor structures of the plurality of semiconductor structures is transferred from the semiconductor wafer to the host substrate to provide a semiconductor device having a substrate formed of the second substrate material.
    Type: Application
    Filed: August 9, 2005
    Publication date: February 15, 2007
    Inventor: Sandeep Bahl
  • Publication number: 20070029589
    Abstract: CMOS image sensor having high sensitivity and low crosstalk, particularly at far-red to infrared wavelengths, and a method for fabricating a CMOS image sensor. A CMOS image sensor has a substrate, an epitaxial layer above the substrate, and a plurality of pixels extending into the epitaxial layer for receiving light. The image sensor also includes at least one of a horizontal barrier layer between the substrate and the epitaxial layer for preventing carriers generated in the substrate from moving to the epitaxial layer, and a plurality of lateral barrier layers between adjacent ones of the plurality of pixels for preventing lateral diffusion of electrons in the epitaxial layer.
    Type: Application
    Filed: August 4, 2005
    Publication date: February 8, 2007
    Inventors: Sandeep Bahl, Fredrick LaMaster, David Bigelow
  • Publication number: 20060267151
    Abstract: In one aspect, a semiconductor device includes a p-region and an n-region. The p-region includes a first Group IV semiconductor that has a bandgap and is doped with a p-type dopant, and a first region of local crystal modifications inducing localized strain that increases the bandgap of the first Group IV semiconductor and creates a conduction band energy barrier against transport of electrons across the p-region. The n-region includes a second Group IV semiconductor that has a bandgap and is doped with an n-type dopant, and a second region of local crystal modifications inducing localized strain that increases the bandgap of the second Group IV semiconductor and creates a valence band energy barrier against transport of holes across the n-region.
    Type: Application
    Filed: May 26, 2005
    Publication date: November 30, 2006
    Inventors: Sandeep Bahl, Glenn Rankin
  • Publication number: 20060270086
    Abstract: In one aspect, a first region that includes a first Group IV semiconductor that has a bandgap and is doped with a first dopant of a first electrical conductivity type is formed. A pattern is created. The pattern controls formation of local crystal modifications in the first Group IV semiconductor in an array. An array of local crystal modifications is formed in the first Group IV semiconductor in accordance with the pattern. The local crystal modifications induce overlapping strain fields that increase the bandgap of the first Group IV semiconductor, create an energy band barrier against transport of minority carriers across the first region. A second region that includes a second Group IV semiconductor that has a bandgap and is doped with a second dopant of a second electrical conductivity type opposite the first conductivity type is formed. Semiconductor devices formed in accordance with this method also are described.
    Type: Application
    Filed: May 26, 2005
    Publication date: November 30, 2006
    Inventors: Glenn Rankin, Sandeep Bahl
  • Patent number: 6992337
    Abstract: A heterojunction bipolar transistor (HBT), comprises a collector formed over a substrate, a base formed over the collector, an emitter formed over the base, and a tunneling suppression layer between the collector and the base, the tunneling suppression layer fabricated from a material that is different from a material of the base and that has an electron affinity equal to or greater than an electron affinity of the material of the base.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: January 31, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Sandeep Bahl, Nicolas J. Moll
  • Publication number: 20050218428
    Abstract: A heterojunction bipolar transistor (HBT), comprises a collector formed over a substrate, a base formed over the collector, an emitter formed over the base, and a tunneling suppression layer between the collector and the base, the tunneling suppression layer fabricated from a material that is different from a material of the base and that has an electron affinity equal to or greater than an electron affinity of the material of the base.
    Type: Application
    Filed: April 2, 2004
    Publication date: October 6, 2005
    Inventors: Sandeep Bahl, Nicolas Moll
  • Patent number: 6583044
    Abstract: A buried channel and a method of fabricating a buried channel in a substrate including depositing a layer of masking material onto a surface of a substrate, etching a groove in the masking layer, etching a channel into the substrate through the groove, and depositing a cover layer over the masking layer and groove such that the covering layer at least substantially closes over the groove.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: June 24, 2003
    Assignee: Agilent Technologies, Inc.
    Inventors: Sandeep Bahl, Karen L. Seaward
  • Publication number: 20020197802
    Abstract: A buried channel and a method of fabricating a buried channel in a substrate including depositing a layer of masking material onto a surface of a substrate, etching a groove in the masking layer, etching a channel into the substrate through the groove, and depositing a cover layer over the masking layer and groove such that the covering layer at least substantially closes over the groove.
    Type: Application
    Filed: June 26, 2001
    Publication date: December 26, 2002
    Inventors: Sandeep Bahl, Karen L. Seaward