Patents by Inventor Daniel J. Lichtenwalner

Daniel J. Lichtenwalner 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: 20250338547
    Abstract: Gate trench semiconductor devices having reduced capacitance between a semiconductor layer structure and a gate electrode thereof. For example, a semiconductor device may include a semiconductor layer structure that comprises a drift region having a first conductivity type, a well layer having a second conductivity type, and a source region having the first conductivity type; a first gate trench extending into an upper portion of the semiconductor layer structure; a first dielectric layer within the first gate trench and conforming to an interior perimeter of the first gate trench; and a first gate electrode within the first gate trench and on the first dielectric layer. The gate electrode may have first and second portions that are spaced apart from each other by a second dielectric layer.
    Type: Application
    Filed: April 26, 2024
    Publication date: October 30, 2025
    Inventors: Daniel J. Lichtenwalner, Shane Stein, Woongsun Kim, Naeem Islam
  • Publication number: 20250311318
    Abstract: A semiconductor device such as a MOSFET or IGBT comprises a semiconductor layer structure that comprises a drift region, a plurality of well regions having a second conductivity type on the drift region, and a plurality of source regions having a first conductivity type on the well regions.
    Type: Application
    Filed: April 1, 2024
    Publication date: October 2, 2025
    Inventors: Madankumar Sampath, Woongsun Kim, Naeem Islam, Daniel J. Lichtenwalner, Jeff Kim, Sei-Hyung Ryu
  • Patent number: 12279448
    Abstract: Semiconductor devices and methods of forming a semiconductor device that includes a polysilicon layer that may improve device reliability and/or a functioning of the device. An example device may include a wide band-gap semiconductor layer structure including a drift region that has a first conductivity type; a plurality of gate trenches in an upper portion of the semiconductor layer structure, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; and a plurality of polysilicon layers, each polysilicon layer on the second sidewall of a respective gate trench.
    Type: Grant
    Filed: June 3, 2022
    Date of Patent: April 15, 2025
    Assignee: Wolfspeed, Inc.
    Inventors: Woongsun Kim, Daniel J. Lichtenwalner, Naeem Islam, Sei-Hyung Ryu
  • Publication number: 20240429323
    Abstract: A Schottky diode includes a semiconductor layer structure that is interposed between first and second contacts. The semiconductor layer structure comprises a current spreading layer having a first conductivity type, a drift region between the second contact and the current spreading layer, the drift region having the first conductivity type, and a first blocking junction having a second conductivity type that is opposite the first conductivity type, the first blocking junction extending downwardly from an upper surface of the semiconductor layer structure. The current spreading layer has a first conductivity type dopant concentration that is at least 1.5 times greater than a first conductivity type dopant concentration of the drift region and the current spreading layer vertically overlaps at least a portion of a lower half of the first blocking junction.
    Type: Application
    Filed: June 23, 2023
    Publication date: December 26, 2024
    Inventors: Jae-Hyung Park, In-Hwan Ji, Daniel J. Lichtenwalner, Edward Robert Van Brunt
  • Publication number: 20240413197
    Abstract: devices and methods of forming a semiconductor device that includes a deep shielding pattern that may improve a reliability and/or a functioning of the device. An example method may include forming a wide band-gap semiconductor layer structure on a substrate, the semiconductor layer structure including a drift region that has a first conductivity type; forming a plurality of gate trenches in an upper portion of the semiconductor layer structure, the gate trenches spaced apart from each other, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; forming an obstruction over a portion of each gate trench that partially obscures the upper opening; and implanting dopants having a second conductivity type that is opposite the first conductivity type into the bottom surfaces of the gate trenches, where the dopants implanted into the bottom surface of the gate trenches form deep shielding patterns.
    Type: Application
    Filed: August 23, 2024
    Publication date: December 12, 2024
    Inventors: Daniel J. Lichtenwalner, Naeem Islam, Woongsun Kim, Sei-Hyung Ryu
  • Patent number: 12094926
    Abstract: Semiconductor devices and methods of forming a semiconductor device that includes a deep shielding pattern that may improve a reliability and/or a functioning of the device. An example method may include forming a wide band-gap semiconductor layer structure on a substrate, the semiconductor layer structure including a drift region that has a first conductivity type; forming a plurality of gate trenches in an upper portion of the semiconductor layer structure, the gate trenches spaced apart from each other, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; forming an obstruction over a portion of each gate trench that partially obscures the upper opening; and implanting dopants having a second conductivity type that is opposite the first conductivity type into the bottom surfaces of the gate trenches, where the dopants implanted into the bottom surface of the gate trenches form deep shielding patterns.
    Type: Grant
    Filed: August 14, 2020
    Date of Patent: September 17, 2024
    Assignee: Wolfspeed, Inc.
    Inventors: Daniel J. Lichtenwalner, Naeem Islam, Woongsun Kim, Sei-Hyung Ryu
  • Patent number: 11929420
    Abstract: A semiconductor device includes a semiconductor layer structure that comprises silicon carbide, a gate dielectric layer on the semiconductor layer structure, the gate dielectric layer including a base gate dielectric layer that is on the semiconductor layer structure and a capping gate dielectric layer on the base gate dielectric layer opposite the semiconductor layer structure, and a gate electrode on the gate dielectric layer opposite the semiconductor layer structure. A dielectric constant of the capping gate dielectric layer is higher than a dielectric constant of the base gate dielectric layer.
    Type: Grant
    Filed: February 10, 2022
    Date of Patent: March 12, 2024
    Assignee: Wolfspeed, Inc.
    Inventor: Daniel J. Lichtenwalner
  • Patent number: 11837629
    Abstract: Semiconductor devices include a semiconductor layer structure comprising a drift region that includes a wide band-gap semiconductor material. A shielding pattern is provided in an upper portion of the drift region in an active region of the device and a termination structure is provided in the upper portion of the drift region in a termination region of the device. A gate trench extends into an upper surface of the semiconductor layer structure. The semiconductor layer structure includes a semiconductor layer that extends above and at least partially covers the termination structure.
    Type: Grant
    Filed: November 19, 2020
    Date of Patent: December 5, 2023
    Assignee: Wolfspeed, Inc.
    Inventors: Daniel J. Lichtenwalner, Edward R. Van Brunt, Brett Hull
  • Patent number: 11837657
    Abstract: A power semiconductor device comprises a semiconductor layer structure having a wide band-gap drift region having a first conductivity type, a gate trench having first and second opposed sidewalls that extend in a first direction in an upper portion of the semiconductor layer structure, first and second well regions having a second conductivity type in the upper portion of the semiconductor layer structure, the first well region comprising part of the first sidewall and the second well region comprising part of the second sidewall. A deep shielding region having the second conductivity type is provided underneath the gate trench, and a plurality of deep shielding connection patterns that have the second conductivity type are provided that electrically connect the deep shielding region to the first and second well regions. The deep shielding connection patterns are spaced apart from each other along the first direction.
    Type: Grant
    Filed: February 15, 2023
    Date of Patent: December 5, 2023
    Assignee: Wolfspeed, Inc.
    Inventors: Naeem Islam, Woongsun Kim, Daniel J. Lichtenwalner, Sei-Hyung Ryu
  • Patent number: 11791378
    Abstract: Semiconductor devices include a silicon carbide drift region having an upper portion and a lower portion. A first contact is on the upper portion of the drift region and a second contact is on the lower portion of the drift region. The drift region includes a superjunction structure that includes a p-n junction that is formed at an angle of between 10° and 30° from a plane that is normal to a top surface of the drift region. The p-n junction extends within +/?1.5° of a crystallographic axis of the silicon carbide material forming the drift region.
    Type: Grant
    Filed: July 9, 2021
    Date of Patent: October 17, 2023
    Assignee: Wolfspeed, Inc.
    Inventors: Edward Robert Van Brunt, Alexander V. Suvorov, Vipindas Pala, Daniel J. Lichtenwalner, Qingchun Zhang
  • Publication number: 20230207686
    Abstract: A power semiconductor device comprises a semiconductor layer structure having a wide band-gap drift region having a first conductivity type, a gate trench having first and second opposed sidewalls that extend in a first direction in an upper portion of the semiconductor layer structure, first and second well regions having a second conductivity type in the upper portion of the semiconductor layer structure, the first well region comprising part of the first sidewall and the second well region comprising part of the second sidewall. A deep shielding region having the second conductivity type is provided underneath the gate trench, and a plurality of deep shielding connection patterns that have the second conductivity type are provided that electrically connect the deep shielding region to the first and second well regions. The deep shielding connection patterns are spaced apart from each other along the first direction.
    Type: Application
    Filed: February 15, 2023
    Publication date: June 29, 2023
    Inventors: Naeem Islam, Woongsun Kim, Daniel J. Lichtenwalner, Sei-Hyung Ryu
  • Patent number: 11610991
    Abstract: A power semiconductor device comprises a semiconductor layer structure having a wide band-gap drift region having a first conductivity type, a gate trench having first and second opposed sidewalls that extend in a first direction in an upper portion of the semiconductor layer structure, first and second well regions having a second conductivity type in the upper portion of the semiconductor layer structure, the first well region comprising part of the first sidewall and the second well region comprising part of the second sidewall. A deep shielding region having the second conductivity type is provided underneath the gate trench, and a plurality of deep shielding connection patterns that have the second conductivity type are provided that electrically connect the deep shielding region to the first and second well regions. The deep shielding connection patterns are spaced apart from each other along the first direction.
    Type: Grant
    Filed: October 28, 2020
    Date of Patent: March 21, 2023
    Assignee: Wolfspeed, Inc.
    Inventors: Naeem Islam, Woongsun Kim, Daniel J. Lichtenwalner, Sei-Hyung Ryu
  • Patent number: 11563101
    Abstract: A semiconductor device includes a semiconductor layer structure that comprises silicon carbide, a gate dielectric layer on the semiconductor layer structure, the gate dielectric layer including a base gate dielectric layer that is on the semiconductor layer structure and a capping gate dielectric layer on the base gate dielectric layer opposite the semiconductor layer structure, and a gate electrode on the gate dielectric layer opposite the semiconductor layer structure. A dielectric constant of the capping gate dielectric layer is higher than a dielectric constant of the base gate dielectric layer.
    Type: Grant
    Filed: July 7, 2020
    Date of Patent: January 24, 2023
    Assignee: Wolfspeed, Inc.
    Inventor: Daniel J. Lichtenwalner
  • Publication number: 20220293787
    Abstract: Semiconductor devices and methods of forming a semiconductor device that includes a polysilicon layer that may improve device reliability and/or a functioning of the device. An example device may include a wide band-gap semiconductor layer structure including a drift region that has a first conductivity type; a plurality of gate trenches in an upper portion of the semiconductor layer structure, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; and a plurality of polysilicon layers, each polysilicon layer on the second sidewall of a respective gate trench.
    Type: Application
    Filed: June 3, 2022
    Publication date: September 15, 2022
    Inventors: Woongsun Kim, Daniel J. Lichtenwalner, Naeem Islam, Sei-Hyung Ryu
  • Patent number: 11355630
    Abstract: Semiconductor devices and methods of forming a semiconductor device that includes a polysilicon layer that may improve device reliability and/or a functioning of the device. An example device may include a wide band-gap semiconductor layer structure including a drift region that has a first conductivity type; a plurality of gate trenches in an upper portion of the semiconductor layer structure, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; and a plurality of polysilicon layers, each polysilicon layer on the second sidewall of a respective gate trench.
    Type: Grant
    Filed: September 11, 2020
    Date of Patent: June 7, 2022
    Assignee: Wolfspeed, Inc.
    Inventors: Woongsun Kim, Daniel J. Lichtenwalner, Naeem Islam, Sei-Hyung Ryu
  • Publication number: 20220165862
    Abstract: A semiconductor device includes a semiconductor layer structure that comprises silicon carbide, a gate dielectric layer on the semiconductor layer structure, the gate dielectric layer including a base gate dielectric layer that is on the semiconductor layer structure and a capping gate dielectric layer on the base gate dielectric layer opposite the semiconductor layer structure, and a gate electrode on the gate dielectric layer opposite the semiconductor layer structure. A dielectric constant of the capping gate dielectric layer is higher than a dielectric constant of the base gate dielectric layer.
    Type: Application
    Filed: February 10, 2022
    Publication date: May 26, 2022
    Inventor: Daniel J. Lichtenwalner
  • Publication number: 20220130996
    Abstract: A power semiconductor device comprises a semiconductor layer structure having a wide band-gap drift region having a first conductivity type, a gate trench having first and second opposed sidewalls that extend in a first direction in an upper portion of the semiconductor layer structure, first and second well regions having a second conductivity type in the upper portion of the semiconductor layer structure, the first well region comprising part of the first sidewall and the second well region comprising part of the second sidewall. A deep shielding region having the second conductivity type is provided underneath the gate trench, and a plurality of deep shielding connection patterns that have the second conductivity type are provided that electrically connect the deep shielding region to the first and second well regions. The deep shielding connection patterns are spaced apart from each other along the first direction.
    Type: Application
    Filed: October 28, 2020
    Publication date: April 28, 2022
    Inventors: Naeem Islam, Woongsun Kim, Daniel J. Lichtenwalner, Sei-Hyung Ryu
  • Publication number: 20220085205
    Abstract: Semiconductor devices and methods of forming a semiconductor device that includes a polysilicon layer that may improve device reliability and/or a functioning of the device. An example device may include a wide band-gap semiconductor layer structure including a drift region that has a first conductivity type; a plurality of gate trenches in an upper portion of the semiconductor layer structure, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; and a plurality of polysilicon layers, each polysilicon layer on the second sidewall of a respective gate trench.
    Type: Application
    Filed: September 11, 2020
    Publication date: March 17, 2022
    Inventors: Woongsun Kim, Daniel J. Lichtenwalner, Naeem Islam, Sei-Hyung Ryu
  • Publication number: 20220052152
    Abstract: Semiconductor devices and methods of forming a semiconductor device that includes a deep shielding pattern that may improve a reliability and/or a functioning of the device. An example method may include forming a wide band-gap semiconductor layer structure on a substrate, the semiconductor layer structure including a drift region that has a first conductivity type; forming a plurality of gate trenches in an upper portion of the semiconductor layer structure, the gate trenches spaced apart from each other, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; forming an obstruction over a portion of each gate trench that partially obscures the upper opening; and implanting dopants having a second conductivity type that is opposite the first conductivity type into the bottom surfaces of the gate trenches, where the dopants implanted into the bottom surface of the gate trenches form deep shielding patterns.
    Type: Application
    Filed: August 14, 2020
    Publication date: February 17, 2022
    Inventors: Daniel J. Lichtenwalner, Naeem Islam, Woongsun Kim, Sei-Hyung Ryu
  • Publication number: 20210367029
    Abstract: Semiconductor devices include a silicon carbide drift region having an upper portion and a lower portion. A first contact is on the upper portion of the drift region and a second contact is on the lower portion of the drift region. The drift region includes a superjunction structure that includes a p-n junction that is formed at an angle of between 10° and 30° from a plane that is normal to a top surface of the drift region. The p-n junction extends within +/?1.5° of a crystallographic axis of the silicon carbide material forming the drift region.
    Type: Application
    Filed: July 9, 2021
    Publication date: November 25, 2021
    Inventors: Edward Robert Van Brunt, Alexander V. Suvorov, Vipindas Pala, Daniel J. Lichtenwalner, Qingchun Zhang