Patents by Inventor Sei-Hyung Ryu

Sei-Hyung Ryu 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: 20220130998
    Abstract: A power semiconductor device comprises a semiconductor layer structure comprising a drift region that comprises a wide band-gap semiconductor material that has a first conductivity type, a well region that has a second conductivity type, and a source region that has the first conductivity type in an upper portion of the well region and a gate trench in an upper portion of the semiconductor layer structure and comprising a portion obliquely angled in plan view. Sidewalls of the gate trench may extend along substantially the same crystal plane in the semiconductor layer structure.
    Type: Application
    Filed: July 23, 2021
    Publication date: April 28, 2022
    Inventors: Woongsun Kim, Daniel Jenner Lichtenwalner, Sei-Hyung Ryu, Naeem Islam
  • 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
  • Patent number: 11309413
    Abstract: A semiconductor device includes a substrate, a drift layer, a well region, and a source region. The substrate has a first conductivity type. The drift layer has the first conductivity type and is on the substrate. The well region has a second conductivity type opposite the first conductivity type and provides a channel region. The source region is in the well region and has the first conductivity type. A doping concentration of the well region along a surface of the drift layer opposite the substrate is variable such that the well region includes a region of increased doping concentration at a distance from a junction between the source region and the well region.
    Type: Grant
    Filed: October 10, 2019
    Date of Patent: April 19, 2022
    Assignee: WOLFSPEED, INC.
    Inventor: 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: 20220069138
    Abstract: A power semiconductor device has a semiconductor layer structure that includes a silicon carbide drift region having a first conductivity type, first and second wells in the silicon carbide drift region that are doped with dopants having a second conductivity type, and a JFET region between the first and second wells. The first and second wells each include a main well and a side well that is between the main well and the JFET region, and each side well includes a respective channel region. A doping concentration of the JFET region exceeds a doping concentration of the silicon carbide drift region, and a minimum width of an upper portion of the JFET region is greater than a minimum width of a lower portion of the JFET region.
    Type: Application
    Filed: August 27, 2020
    Publication date: March 3, 2022
    Inventors: Kijeong Han, Joohyung Kim, 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
  • Patent number: 11184001
    Abstract: Power switching devices include a semiconductor layer structure that has an active region and an inactive region. The active region includes a plurality of unit cells and the inactive region includes a field insulating layer on the semiconductor layer structure and a gate bond pad on the field insulating layer opposite the semiconductor layer structure. A gate insulating pattern is provided on the semiconductor layer structure between the active region and the field insulating layer, and at least one source/drain contact is provided on the semiconductor layer structure between the gate insulating pattern and the field insulating layer.
    Type: Grant
    Filed: March 6, 2020
    Date of Patent: November 23, 2021
    Assignee: Cree, Inc.
    Inventors: Qingchun Zhang, Adam Barkley, Sei-Hyung Ryu, Brett Hull
  • Publication number: 20210273090
    Abstract: A semiconductor die includes a drift region, an active region in the drift region, and an edge termination region surrounding the active region in the drift region. The drift region has a first doping type. The edge termination region includes a charge compensation region, a number of guard rings, and a counter doping region. The charge compensation region is in the drift region and has a second doping type that is opposite the first doping type. The guard rings are in the charge compensation region, have the second doping type, and a doping concentration that is greater than a doping concentration of the charge compensation region. The counter doping region is in the drift region and overlaps at least a portion of the charge compensation region. The counter doping region has the first doping type.
    Type: Application
    Filed: March 2, 2020
    Publication date: September 2, 2021
    Inventors: Philipp Steinmann, Edward Robert Van Brunt, Sei-Hyung Ryu, Jae-Hyung Park
  • Patent number: 11075295
    Abstract: A metal-oxide-semiconductor field-effect transistor includes a wide bandgap substrate, a wide bandgap drift layer over the substrate, a number of junction implants in the drift layer, and a JFET region between the junction implants. The JFET region is defined by a JFET gap, which is the distance between adjacent ones of the junction implants. The JFET gap is not uniform throughout the MOSFET device. The JFET region is separated into a first JFET sub-region and a second JFET sub-region, such that a doping concentration in the first JFET sub-region is different from a doping concentration in the second JFET sub-region.
    Type: Grant
    Filed: July 13, 2018
    Date of Patent: July 27, 2021
    Assignee: Cree, Inc.
    Inventor: Sei-Hyung Ryu
  • Patent number: 11057033
    Abstract: A power module includes a plurality of power semiconductor devices. The plurality of power semiconductor devices includes an insulated gate bipolar transistor (IGBT) and a metal-oxide-semiconductor field-effect transistor (MOSFET) coupled in parallel between a first power switching terminal and a second power switching terminal. The IGBT and the MOSFET are silicon carbide devices. By providing the IGBT and the MOSFET together, a tradeoff between forward conduction current and reverse conduction current of the power module, the efficiency, and the specific current rating of the power module may be improved. Further, providing the IGBT and the MOSFET as silicon carbide devices may significantly improve the performance of the power module.
    Type: Grant
    Filed: July 8, 2019
    Date of Patent: July 6, 2021
    Assignee: Cree, Inc.
    Inventors: Edward Robert Van Brunt, Adam Barkley, Sei-Hyung Ryu, Zachary Cole, Kraig J. Olejniczak
  • Publication number: 20210202341
    Abstract: Shielding techniques are used to provide an embedded sensor element such as a temperature sensing element on a wide bandgap power semiconductor device. A semiconductor device may include a drift layer and an embedded sensor element. The drift layer may be a wide bandgap semiconductor material. A shielding structure is provided in the drift layer below the embedded sensor element. The embedded sensor element may be provided between contacts that are in electrical contact with the shielding well. The distance between the contacts may be minimized. A noise reduction well may be provided between the contacts to further isolate the embedded sensor element from parasitic signals.
    Type: Application
    Filed: March 15, 2021
    Publication date: July 1, 2021
    Inventors: Joohyung Kim, Sei-Hyung Ryu, Kijeong Han, Thomas E. Harrington, III, Edward Robert Van Brunt
  • Patent number: 11024731
    Abstract: A power module is disclosed that includes a housing with an interior chamber wherein multiple switch modules are mounted within the interior chamber. The switch modules comprise multiple transistors and diodes that are interconnected to facilitate switching power to a load. In one embodiment, at least one of the switch modules supports a current density of at least 10 amperes per cm2.
    Type: Grant
    Filed: October 26, 2018
    Date of Patent: June 1, 2021
    Assignee: Cree, Inc.
    Inventors: Jason Patrick Henning, Qingchun Zhang, Sei-Hyung Ryu, Anant Kumar Agarwal, John Williams Palmour, Scott Allen
  • Publication number: 20210111279
    Abstract: A semiconductor device includes a substrate, a drift layer, a well region, and a source region. The substrate has a first conductivity type. The drift layer has the first conductivity type and is on the substrate. The well region has a second conductivity type opposite the first conductivity type and provides a channel region. The source region is in the well region and has the first conductivity type. A doping concentration of the well region along a surface of the drift layer opposite the substrate is variable such that the well region includes a region of increased doping concentration at a distance from a junction between the source region and the well region.
    Type: Application
    Filed: October 10, 2019
    Publication date: April 15, 2021
    Inventor: Sei-Hyung Ryu
  • Publication number: 20200412359
    Abstract: A power module includes a plurality of power semiconductor devices. The plurality of power semiconductor devices includes an insulated gate bipolar transistor (IGBT) and a metal-oxide-semiconductor field-effect transistor (MOSFET) coupled in parallel between a first power switching terminal and a second power switching terminal. The IGBT and the MOSFET are silicon carbide devices. By providing the IGBT and the MOSFET together, a tradeoff between forward conduction current and reverse conduction current of the power module, the efficiency, and the specific current rating of the power module may be improved. Further, providing the IGBT and the MOSFET as silicon carbide devices may significantly improve the performance of the power module.
    Type: Application
    Filed: July 8, 2019
    Publication date: December 31, 2020
    Inventors: Edward Robert Van Brunt, Adam Barkley, Sei-Hyung Ryu, Zachary Cole, Kraig J. Olejniczak
  • Publication number: 20200365721
    Abstract: A vertical semiconductor device includes one or more of a substrate, a buffer layer over the substrate, one or more drift layers over the buffer layer, and a spreading layer over the one or more drift layers.
    Type: Application
    Filed: July 24, 2020
    Publication date: November 19, 2020
    Inventors: Daniel Jenner Lichtenwalner, Sei-Hyung Ryu, Kijeong Han, Edward Robert Van Brunt
  • Publication number: 20200212908
    Abstract: Power switching devices include a semiconductor layer structure that has an active region and an inactive region. The active region includes a plurality of unit cells and the inactive region includes a field insulating layer on the semiconductor layer structure and a gate bond pad on the field insulating layer opposite the semiconductor layer structure. A gate insulating pattern is provided on the semiconductor layer structure between the active region and the field insulating layer, and at least one source/drain contact is provided on the semiconductor layer structure between the gate insulating pattern and the field insulating layer.
    Type: Application
    Filed: March 6, 2020
    Publication date: July 2, 2020
    Inventors: Qingchun Zhang, Adam Barkley, Sei-Hyung Ryu, Brett Hull
  • Patent number: 10601413
    Abstract: Power switching devices include a semiconductor layer structure that has an active region and an inactive region. The active region includes a plurality of unit cells and the inactive region includes a field insulating layer on the semiconductor layer structure and a gate bond pad on the field insulating layer opposite the semiconductor layer structure. A gate insulating pattern is provided on the semiconductor layer structure between the active region and the field insulating layer, and at least one source/drain contact is provided on the semiconductor layer structure between the gate insulating pattern and the field insulating layer.
    Type: Grant
    Filed: September 8, 2017
    Date of Patent: March 24, 2020
    Assignee: Cree, Inc.
    Inventors: Qingchun Zhang, Adam Barkley, Sei-Hyung Ryu, Brett Hull
  • Publication number: 20200020793
    Abstract: A metal-oxide-semiconductor field-effect transistor includes a wide bandgap substrate, a wide bandgap drift layer over the substrate, a number of junction implants in the drift layer, and a JFET region between the junction implants. The JFET region is defined by a JFET gap, which is the distance between adjacent ones of the junction implants. The JFET gap is not uniform throughout the MOSFET device. The JFET region is separated into a first JFET sub-region and a second JFET sub-region, such that a doping concentration in the first JFET sub-region is different from a doping concentration in the second JFET sub-region.
    Type: Application
    Filed: July 13, 2018
    Publication date: January 16, 2020
    Inventor: Sei-Hyung Ryu
  • Patent number: 10269955
    Abstract: A vertical FET includes a silicon carbide substrate having a top surface and a bottom surface opposite the top surface; a drain/collector contact on the bottom surface of the silicon carbide substrate; and an epitaxial structure on the top surface of the silicon carbide substrate having formed therein a first source/emitter implant. A gate dielectric is provided on a portion of the epitaxial structure. First source/emitter contact segments are spaced apart from each other and on the first source/emitter implant. A first elongated gate contact and a second elongated gate contact are on the gate dielectric and positioned such that the first source/emitter implant is below and between the first elongated gate contact and the second elongated gate contact. Inter-gate plates extend from at least one of the first elongated gate contact and the second elongated gate contact into spaces formed between the first source/emitter contact segments.
    Type: Grant
    Filed: January 17, 2017
    Date of Patent: April 23, 2019
    Assignee: Cree, Inc.
    Inventors: Sei-Hyung Ryu, Marcelo Schupbach, Adam Barkley, Scott Allen
  • Publication number: 20190081624
    Abstract: Power switching devices include a semiconductor layer structure that has an active region and an inactive region. The active region includes a plurality of unit cells and the inactive region includes a field insulating layer on the semiconductor layer structure and a gate bond pad on the field insulating layer opposite the semiconductor layer structure. A gate insulating pattern is provided on the semiconductor layer structure between the active region and the field insulating layer, and at least one source/drain contact is provided on the semiconductor layer structure between the gate insulating pattern and the field insulating layer.
    Type: Application
    Filed: September 8, 2017
    Publication date: March 14, 2019
    Inventors: Qingchun Zhang, Adam Barkley, Sei-Hyung Ryu, Brett Hull