Patents by Inventor Chris Hardiman

Chris Hardiman 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: 20240429230
    Abstract: A semiconductor device includes a semiconductor structure comprising first and second semiconductor layers having different bandgaps, first and second contacts on the semiconductor structure and free of a gate structure therebetween, and a resistor comprising a portion of the semiconductor structure that electrically connects the first and second contacts. The portion of the semiconductor structure may be a second portion of the second semiconductor layer that is recessed in thickness relative to a first portion thereof, and/or may include a passivation layer in direct contact with the second semiconductor layer. Related devices, packages, and fabrication methods are discussed.
    Type: Application
    Filed: June 20, 2023
    Publication date: December 26, 2024
    Inventors: Matthew King, Chris Hardiman, Kyle Bothe, Jeremy Fisher
  • Publication number: 20240421193
    Abstract: Semiconductor devices with reduced contact resistance of ohmic contacts are provided. In one example, the semiconductor device includes a Group III-nitride semiconductor structure. The Group III-nitride semiconductor structure includes a channel layer and a barrier layer on the channel layer. The semiconductor device includes an implanted region extending into the channel layer. The implanted region includes a distribution of implanted dopants. The semiconductor device includes a recess in the implanted region. The recess extends through the barrier layer into the channel layer. The semiconductor device includes an ohmic contact within the recess.
    Type: Application
    Filed: June 13, 2023
    Publication date: December 19, 2024
    Inventors: Kyle Bothe, Jia Guo, Christer Hallin, Alexander V. Suvorov, Chris Hardiman, Scott Sheppard
  • Publication number: 20240304702
    Abstract: Field reducing structures for transistor devices having Group III-nitride semiconductor structures are provided. In one example, a transistor device includes a nitrogen-polar (N-polar) Group III-nitride semiconductor structure. The transistor device includes a source contact, a drain contact, and a gate contact. The transistor device includes a field reducing structure operable to reduce an electric field in a region in the N-polar Group III-nitride semiconductor structure between the gate contact and the drain contact.
    Type: Application
    Filed: March 6, 2023
    Publication date: September 12, 2024
    Inventors: Kyle Bothe, Chris Hardiman, Scott Sheppard
  • Publication number: 20240290847
    Abstract: Semiconductor devices having nitrogen-polar (N-polar) Group III-nitride semiconductor structures are provided. In one example, a semiconductor device may include a nitrogen polar (N-polar) Group III-nitride semiconductor structure. The N-polar Group III-nitride semiconductor structure may have a first surface and a second surface opposing the first surface. The semiconductor device may include an electrode. The semiconductor device may include a low-k dielectric layer located between the first surface of the N-polar Group III-nitride semiconductor structure and at least a portion of the electrode. The low-k dielectric layer may have a dielectric constant of less than about 3.9. In some examples, the N-polar Group III-nitride semiconductor structure may include a trench extending at least partially into one or more cap layers of the N-polar Group III-nitride semiconductor structure.
    Type: Application
    Filed: February 27, 2023
    Publication date: August 29, 2024
    Inventors: Kyle Bothe, Chris Hardiman, Scott Sheppard
  • Publication number: 20240290876
    Abstract: Semiconductor device having nitrogen-polar (N-polar) Group III-nitride structures are provided. In one example, a semiconductor device may include an N-polar Group III-nitride semiconductor structure. The N-polar Group III-nitride semiconductor structure may have a first region and a second region. The N-polar Group III-nitride semiconductor structure may have a first surface and a second surface opposing the first surface. The second surface may be a planar surface. The semiconductor device may include an isolation implant region extending from the second surface into the N-polar Group III-nitride semiconductor structure to a depth sufficient to provide electrical isolation between the first region and the second region of the N-polar Group III-nitride semiconductor structure.
    Type: Application
    Filed: February 23, 2023
    Publication date: August 29, 2024
    Inventors: Kyle Bothe, Chris Hardiman, Scott Sheppard
  • Publication number: 20240274507
    Abstract: Semiconductor devices are provided. In one example, a semiconductor device includes a substrate. The semiconductor device includes a nitrogen-polar (N-polar) Group III-nitride semiconductor structure on the substrate. The semiconductor device includes a via passing through the substrate and the N-polar Group III-nitride semiconductor structure. A cross-sectional profile of the via changes at an interface between the substrate and the N-polar Group III-nitride semiconductor structure.
    Type: Application
    Filed: February 14, 2023
    Publication date: August 15, 2024
    Inventors: Kyle Bothe, Chris Hardiman, Scott Sheppard
  • Publication number: 20240194751
    Abstract: A transistor device includes a semiconductor structure having an implanted region adjacent a surface thereof; and a source/drain contact including an ohmic contact portion on the implanted region of the semiconductor structure. The implanted region laterally extends beyond the ohmic contact portion by less than about 0.8 microns, e.g., by less than about 0.2 microns or such that a boundary of the implanted region is substantially aligned with an edge of the ohmic contact portion. Related fabrication methods are also discussed.
    Type: Application
    Filed: December 9, 2022
    Publication date: June 13, 2024
    Inventors: Kyle Bothe, Chris Hardiman, Chloe Hawes, Daniel Namishia, Evan Jones
  • Publication number: 20240072125
    Abstract: A method of forming ohmic contacts on a semiconductor layer includes forming silicon ohmic contact precursors on the semiconductor layer, depositing a layer of metal on the semiconductor layer including the silicon ohmic contact precursors, reacting the layer of metal with the silicon ohmic contact precursors to form metal silicide ohmic contacts on the semiconductor layer, and selectively removing the layer of metal from the semiconductor layer without removing the metal silicide contacts from the semiconductor layer.
    Type: Application
    Filed: August 23, 2022
    Publication date: February 29, 2024
    Inventors: Kyle Bothe, Evan Jones, Chris Hardiman
  • Publication number: 20240063300
    Abstract: A high electron mobility transistor comprises a semiconductor layer structure that includes a channel layer and a barrier layer and source and drain contacts on the semiconductor layer structure. A gate contact and a multi-layer passivation structure are provided on the semiconductor layer structure between the source contact and the drain contact. The multi-layer passivation structure comprises at least first and second silicon nitride layers that have different material compositions. A spacer passivation layer is provided on sidewalls of the first and second silicon nitride layers. A material composition of the spacer passivation layer is different than a material composition of at least one of the layers of the multi-layer passivation structure.
    Type: Application
    Filed: August 18, 2022
    Publication date: February 22, 2024
    Inventors: Kyle Bothe, Chris Hardiman, Elizabeth Keenan, Jia Guo, Fabian Radulescu, Scott Sheppard
  • Patent number: 11842937
    Abstract: A transistor device includes a substrate, a semiconductor structure on the substrate, a metallization layer comprising a non-planar surface on a surface of the semiconductor structure, a non-planar encapsulation layer on the non-planar surface of the metallization layer, the non-planar encapsulation layer comprising a non-planar encapsulant surface that is opposite the non-planar surface, and a self-planarizing encapsulation layer on the non-planar encapsulation layer and comprising a planarized surface that is opposite the non-planar encapsulant surface.
    Type: Grant
    Filed: July 30, 2021
    Date of Patent: December 12, 2023
    Assignee: Wolfspeed, Inc.
    Inventors: Chris Hardiman, Daniel Namishia, Kyle Bothe, Elizabeth Keenan
  • Publication number: 20230395670
    Abstract: A transistor device includes a semiconductor structure comprising a channel layer and a barrier layer; source and drain contacts on the semiconductor structure; and a gate on the semiconductor structure between the source and drain contacts. A first portion of the barrier layer extending between the source or drain contact and the gate has a first thickness, a second portion of the barrier layer between the gate and the channel layer has a second thickness, and the first thickness is about 1.5 times to 4 times greater than the second thickness. Related methods of fabrication using a looped recess process are also discussed.
    Type: Application
    Filed: June 7, 2022
    Publication date: December 7, 2023
    Inventors: Chris Hardiman, Kyoung-Keun Lee, Kyle Bothe, Fabian Radulescu
  • Publication number: 20230395695
    Abstract: A transistor device includes a semiconductor structure comprising a channel layer and a barrier layer, source and drain contacts on the semiconductor structure, and a conductive element in a recess in the barrier layer between the source and drain contacts. The barrier layer has a first thickness adjacent the source or drain contact, a second thickness at a floor of the recess between the conductive element and the channel layer, and the first thickness is about 1.2 times to 4 times greater than the second thickness. Related methods of fabrication using a looped recess process are also discussed.
    Type: Application
    Filed: May 2, 2023
    Publication date: December 7, 2023
    Inventors: Chris Hardiman, Matthew King, Kyle Bothe
  • Patent number: 11616136
    Abstract: A power amplifier comprising a GaN-based high electron mobility transistor (HEMT) device, wherein a power added efficiency (PAE) of the power amplifier is greater than 32% at P1DB during operation of the power amplifier between 26.5 GHz and 30.5 GHz.
    Type: Grant
    Filed: February 19, 2021
    Date of Patent: March 28, 2023
    Assignee: Wolfspeed, Inc.
    Inventors: Kyle Bothe, Evan Jones, Dan Namishia, Chris Hardiman, Fabian Radulescu, Terry Alcorn, Scott Sheppard, Bruce Schmukler
  • Patent number: 11587842
    Abstract: A semiconductor die includes a substrate, a first passivation layer over the substrate, and a second passivation layer over the first passivation layer and the substrate. The substrate has boundaries defined by a substrate termination edge. The first passivation layer is over the substrate such that it terminates at a first passivation termination edge that is inset from the substrate termination edge by a first distance. The second passivation layer is over the first passivation layer and the substrate such that it terminates at a second passivation termination edge that is inset from the substrate termination edge by a second distance. The second distance is less than the first distance such that the second passivation layer overlaps the first passivation layer.
    Type: Grant
    Filed: October 29, 2020
    Date of Patent: February 21, 2023
    Assignee: Wolfspeed, Inc.
    Inventors: Chris Hardiman, Kyoung-Keun Lee, Fabian Radulescu, Daniel Namishia, Scott Thomas Sheppard
  • Publication number: 20230031205
    Abstract: A transistor device includes a substrate, a semiconductor structure on the substrate, a metallization layer comprising a non-planar surface on a surface of the semiconductor structure, a non-planar encapsulation layer on the non-planar surface of the metallization layer, the non-planar encapsulation layer comprising a non-planar encapsulant surface that is opposite the non-planar surface, and a self-planarizing encapsulation layer on the non-planar encapsulation layer and comprising a planarized surface that is opposite the non-planar encapsulant surface.
    Type: Application
    Filed: July 30, 2021
    Publication date: February 2, 2023
    Inventors: Chris Hardiman, Daniel Namishia, Kyle Bothe, Elizabeth Keenan
  • Publication number: 20210359118
    Abstract: A high-electron mobility transistor (HEMT) that includes a substrate, a group III-Nitride channel layer on the substrate, a group III-Nitride barrier layer on the group III-Nitride channel layer, the group III-Nitride barrier layer that includes a higher bandgap than a bandgap of the group III-Nitride channel layer, a source electrically coupled to the group III-Nitride barrier layer, a gate electrically coupled to the group III-Nitride barrier layer, and a drain electrically coupled to the group III-Nitride barrier layer. The source and/or the drain are structured and arranged to extend through the group III-Nitride barrier layer into the group III-Nitride channel layer.
    Type: Application
    Filed: May 18, 2020
    Publication date: November 18, 2021
    Inventors: Fabian Radulescu, Scott Sheppard, Dan Namishia, Chris Hardiman, Terry Alcorn, Kyle Bothe, Jennifer Gao
  • Publication number: 20210175351
    Abstract: A power amplifier comprising a GaN-based high electron mobility transistor (HEMT) device, wherein a power added efficiency (PAE) of the power amplifier is greater than 32% at P1DB during operation of the power amplifier between 26.5 GHz and 30.5 GHz.
    Type: Application
    Filed: February 19, 2021
    Publication date: June 10, 2021
    Inventors: Kyle Bothe, Evan Jones, Dan Namishia, Chris Hardiman, Fabian Radulescu, Terry Alcorn, Scott Sheppard, Bruce Schmukler
  • Patent number: 10971612
    Abstract: A power amplifier comprising a GaN-based high electron mobility transistor (HEMT) device, wherein a power added efficiency (PAE) of the power amplifier is greater than 32% at P1DB during operation of the power amplifier between 26.5 GHz and 30.5 GHz.
    Type: Grant
    Filed: August 29, 2019
    Date of Patent: April 6, 2021
    Assignee: Cree, Inc.
    Inventors: Kyle Bothe, Evan Jones, Dan Namishia, Chris Hardiman, Fabian Radulescu, Terry Alcorn, Scott Sheppard, Bruce Schmukler
  • Patent number: 10923585
    Abstract: A high electron mobility transistor (HEMT) includes a substrate comprising a first surface and a second surface on opposing sides of the substrate, a channel layer on the first surface of the substrate opposite the substrate, a barrier layer on the channel layer, a source contact comprising a first ohmic contact on an upper surface of the barrier layer, and a via extending from the second surface of the substrate to the first ohmic contact.
    Type: Grant
    Filed: June 13, 2019
    Date of Patent: February 16, 2021
    Assignee: Cree, Inc.
    Inventors: Kyle Bothe, Evan Jones, Dan Namishia, Chris Hardiman, Fabian Radulescu, Jeremy Fisher, Scott Sheppard
  • Publication number: 20210043530
    Abstract: A semiconductor die includes a substrate, a first passivation layer over the substrate, and a second passivation layer over the first passivation layer and the substrate. The substrate has boundaries defined by a substrate termination edge. The first passivation layer is over the substrate such that it terminates at a first passivation termination edge that is inset from the substrate termination edge by a first distance. The second passivation layer is over the first passivation layer and the substrate such that it terminates at a second passivation termination edge that is inset from the substrate termination edge by a second distance. The second distance is less than the first distance such that the second passivation layer overlaps the first passivation layer.
    Type: Application
    Filed: October 29, 2020
    Publication date: February 11, 2021
    Inventors: Chris Hardiman, Kyoung-Keun Lee, Fabian Radulescu, Daniel Namishia, Scott Thomas Sheppard