Patents by Inventor Limin Weng

Limin Weng 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: 10096588
    Abstract: A transient voltage suppressing (TVS) device formed in an epitaxial layer of a first conductivity type supported on a semiconductor substrate. The TVS device further comprises a plurality of contact trenches opened and extended to a lower part of the epitaxial layer filled with a doped polysilicon layer of a second conductivity type wherein the trenches are further surrounded by a heavy dopant region of the second conductivity type. The TVS device further includes a metal contact layer disposed on a top surface of the epitaxial layer electrically connected to a Vcc electrode wherein the metal contact layer further directly contacting the doped polysilicon layer and the heavy dopant region of the second conductivity type.
    Type: Grant
    Filed: September 30, 2017
    Date of Patent: October 9, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Wenjiang Zeng, Limin Weng
  • Publication number: 20180026025
    Abstract: A transient voltage suppressing (TVS) device formed in an epitaxial layer of a first conductivity type supported on a semiconductor substrate. The TVS device further comprises a plurality of contact trenches opened and extended to a lower part of the epitaxial layer filled with a doped polysilicon layer of a second conductivity type wherein the trenches are further surrounded by a heavy dopant region of the second conductivity type. The TVS device further includes a metal contact layer disposed on a top surface of the epitaxial layer electrically connected to a Vcc electrode wherein the metal contact layer further directly contacting the doped polysilicon layer and the heavy dopant region of the second conductivity type.
    Type: Application
    Filed: September 30, 2017
    Publication date: January 25, 2018
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: MADHUR BOBDE, WENJIANG ZENG, LIMIN WENG
  • Patent number: 9793254
    Abstract: A transient voltage suppressing (TVS) device formed in an epitaxial layer of a first conductivity type supported on a semiconductor substrate. The TVS device further comprises a plurality of contact trenches opened and extended to a lower part of the epitaxial layer filled with a doped polysilicon layer of a second conductivity type wherein the trenches are further surrounded by a heavy dopant region of the second conductivity type. The TVS device further includes a metal contact layer disposed on a top surface of the epitaxial layer electrically connected to a Vcc electrode wherein the metal contact layer further directly contacting the doped polysilicon layer and the heavy dopant region of the second conductivity type.
    Type: Grant
    Filed: December 9, 2014
    Date of Patent: October 17, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Wenjiang Zeng, Limin Weng
  • Publication number: 20170141097
    Abstract: A transient voltage suppressing (TVS) device formed in an epitaxial layer of a first conductivity type supported on a semiconductor substrate. The TVS device further comprises a plurality of contact trenches opened and extended to a lower part of the epitaxial layer filled with a doped polysilicon layer of a second conductivity type wherein the trenches are further surrounded by a heavy dopant region of the second conductivity type. The TVS device further includes a metal contact layer disposed on a top surface of the epitaxial layer electrically connected to a Vcc electrode wherein the metal contact layer further directly contacting the doped polysilicon layer and the heavy dopant region of the second conductivity type.
    Type: Application
    Filed: December 9, 2014
    Publication date: May 18, 2017
    Inventors: Madhur Bobde, Wenjiang Zeng, Limin Weng
  • Patent number: 9252265
    Abstract: A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device.
    Type: Grant
    Filed: March 17, 2015
    Date of Patent: February 2, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hong Chang, Yi Su, Wenjun Li, Limin Weng, Gary Chen, Jongoh Kim, John Chen
  • Publication number: 20150194522
    Abstract: A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device.
    Type: Application
    Filed: March 17, 2015
    Publication date: July 9, 2015
    Inventors: Hong Chang, Yi Su, Wenjun Li, Limin Weng, Gary Chen, Jongoh Kim, John Chen
  • Patent number: 8994101
    Abstract: A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device.
    Type: Grant
    Filed: April 18, 2013
    Date of Patent: March 31, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hong Chang, Yi Su, Wenjun Li, Limin Weng, Jongoh Kim, John Chen
  • Patent number: 8835977
    Abstract: A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate of a first conductivity type. The TVS includes a buried dopant region of a second conductivity type disposed and encompassed in an epitaxial layer of the first conductivity type wherein the buried dopant region extends laterally and has an extended bottom junction area interfacing with the underlying portion of the epitaxial layer thus constituting a Zener diode for the TVS device. The TVS device further includes a region above the buried dopant region further comprising a top dopant layer of a second conductivity type and a top contact region of a second conductivity type which act in combination with the epitaxial layer and the buried dopant region to form a plurality of interfacing PN junctions constituting a SCR acting as a steering diode to function with the Zener diode for suppressing a transient voltage.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: September 16, 2014
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Lingpeng Guan, Anup Bhalla, Limin Weng
  • Publication number: 20140167101
    Abstract: A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate of a first conductivity type. The TVS includes a buried dopant region of a second conductivity type disposed and encompassed in an epitaxial layer of the first conductivity type wherein the buried dopant region extends laterally and has an extended bottom junction area interfacing with the underlying portion of the epitaxial layer thus constituting a Zener diode for the TVS device. The TVS device further includes a region above the buried dopant region further comprising a top dopant layer of a second conductivity type and a top contact region of a second conductivity type which act in combination with the epitaxial layer and the buried dopant region to form a plurality of interfacing PN junctions constituting a SCR acting as a steering diode to function with the Zener diode for suppressing a transient voltage.
    Type: Application
    Filed: December 19, 2012
    Publication date: June 19, 2014
    Inventors: Madhur Bobde, Lingpeng Guan, Anup Bhalla, Limin Weng
  • Patent number: 8580676
    Abstract: A semiconductor device formed on a semiconductor substrate may include a component formed in a contact trench located in an active cell region. The component may comprise a barrier metal deposited on a bottom and portions of sidewalls of the contact trench and a tungsten plug deposited in a remaining portion of the contact trench. The barrier metal may comprise first and second metal layers. The first metal layer may be proximate to the sidewall and the bottom of the contact trench. The first metal layer may include a nitride. The second metal layer may be between the first metal layer and the tungsten plug and between the tungsten plug and the sidewall. The second metal layer covers portions of the sidewalls of not covered by the first metal layer.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: November 12, 2013
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hong Chang, John Chen, Limin Weng, Wenjun Li
  • Publication number: 20130228860
    Abstract: A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device.
    Type: Application
    Filed: April 18, 2013
    Publication date: September 5, 2013
    Inventors: Hong Chang, Yi Su, Wenjun Li, Limin Weng, Gary Chen, Jongoh Kim, John Chen
  • Patent number: 8431457
    Abstract: A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: April 30, 2013
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hong Chang, Yi Su, Wenjun Li, Limin Weng, Gary Chen, Jongoh Kim, John Chen
  • Patent number: 8338854
    Abstract: A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate of a first conductivity type. The TVS includes a buried dopant region of a second conductivity type disposed and encompassed in an epitaxial layer of the first conductivity type wherein the buried dopant region extends laterally and has an extended bottom junction area interfacing with the underlying portion of the epitaxial layer thus constituting a Zener diode for the TVS device. The TVS device further includes a region above the buried dopant region further comprising a top dopant layer of a second conductivity type and a top contact region of a second conductivity type which act in combination with the epitaxial layer and the buried dopant region to form a plurality of interfacing PN junctions constituting a SCR acting as a steering diode to function with the Zener diode for suppressing a transient voltage.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: December 25, 2012
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Lingpeng Guan, Anup Bhalla, Limin Weng
  • Publication number: 20120129328
    Abstract: A semiconductor device formed on a semiconductor substrate may include a component formed in a contact trench located in an active cell region. The component may comprise a barrier metal deposited on a bottom and portions of sidewalls of the contact trench and a tungsten plug deposited in a remaining portion of the contact trench. The barrier metal may comprise first and second metal layers. The first metal layer may be proximate to the sidewall and the bottom of the contact trench. The first metal layer may include a nitride. The second metal layer may be between the first metal layer and the tungsten plug and between the tungsten plug and the sidewall. The second metal layer covers portions of the sidewalls of not covered by the first metal layer.
    Type: Application
    Filed: January 30, 2012
    Publication date: May 24, 2012
    Applicant: ALPHA & OMEGA SEMICONDUCTOR, INC.
    Inventors: Hong Chang, John Chen, Limin Weng, Wenjun Li
  • Patent number: 8138605
    Abstract: A semiconductor device formed on a semiconductor substrate may include a component formed in a contact trench located in an active cell region. The component may comprise a barrier metal deposited on a bottom and portions of sidewalls of the contact trench and a tungsten plug deposited in a remaining portion of the contact trench. The barrier metal may comprise first and second metal layers. The first metal layer may be proximate to the sidewall and the bottom of the contact trench. The first metal layer may include a nitride. The second metal layer may be between the first metal layer and the tungsten plug and between the tungsten plug and the sidewall. The second metal layer covers portions of the sidewalls of not covered by the first metal layer.
    Type: Grant
    Filed: October 26, 2009
    Date of Patent: March 20, 2012
    Assignee: Alpha & Omega Semiconductor, Inc.
    Inventors: Hong Chang, John Chen, Limin Weng, Wenjun Li
  • Publication number: 20110220990
    Abstract: A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 15, 2011
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Hong Chang, Yi Su, Wenjun Li, Limin Weng, Gary Chen, Jongoh Kim, John Chen
  • Publication number: 20110095361
    Abstract: A semiconductor device formed on a semiconductor substrate may include a component formed in a contact trench located in an active cell region. The component may comprise a barrier metal deposited on a bottom and portions of sidewalls of the contact trench and a tungsten plug deposited in a remaining portion of the contact trench. The barrier metal may comprise first and second metal layers. The first metal layer may be proximate to the sidewall and the bottom of the contact trench. The first metal layer may include a nitride. The second metal layer may be between the first metal layer and the tungsten plug and between the tungsten plug and the sidewall. The second metal layer covers portions of the sidewalls of not covered by the first metal layer.
    Type: Application
    Filed: October 26, 2009
    Publication date: April 28, 2011
    Applicant: ALPHA & OMEGA SEMICONDUCTOR, INC.
    Inventors: Hong Chang, John Chen, Limin Weng, Wenjun Li
  • Patent number: 7863995
    Abstract: A transient voltage suppressing (TVS) circuit with uni-directional blocking and symmetric bi-directional blocking capabilities integrated with an electromagnetic interference (EMI) filter supported on a semiconductor substrate of a first conductivity type. The TVS circuit integrated with the EMI filter further includes a ground terminal disposed on the surface for the symmetric bi-directional blocking structure and at the bottom of the semiconductor substrate for the uni-directional blocking structure and an input and an output terminal disposed on a top surface with at least a Zener diode and a plurality of capacitors disposed in the semiconductor substrate to couple the ground terminal to the input and output terminals with a direct capacitive coupling without an intermediate floating body region.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: January 4, 2011
    Assignee: Alpha & Omega Semiconductor Ltd.
    Inventors: Moses Ho, Madhur Bobde, Mike Chang, Limin Weng
  • Publication number: 20100244090
    Abstract: A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate of a first conductivity type. The TVS includes a buried dopant region of a second conductivity type disposed and encompassed in an epitaxial layer of the first conductivity type wherein the buried dopant region extends laterally and has an extended bottom junction area interfacing with the underlying portion of the epitaxial layer thus constituting a Zener diode for the TVS device. The TVS device further includes a region above the buried dopant region further comprising a top dopant layer of a second conductivity type and a top contact region of a second conductivity type which act in combination with the epitaxial layer and the buried dopant region to form a plurality of interfacing PN junctions constituting a SCR acting as a steering diode to function with the Zener diode for suppressing a transient voltage.
    Type: Application
    Filed: March 31, 2009
    Publication date: September 30, 2010
    Inventors: Madhur Bobde, Lingpeng Guan, Anup Bhalla, Limin Weng
  • Publication number: 20080310065
    Abstract: A transient voltage suppressing (TVS) circuit with uni-directional blocking and symmetric bi-directional blocking capabilities integrated with an electromagnetic interference (EMI) filter supported on a semiconductor substrate of a first conductivity type. The TVS circuit integrated with the EMI filter further includes a ground terminal disposed on the surface for the symmetric bi-directional blocking structure and at the bottom of the semiconductor substrate for the uni-directional blocking structure and an input and an output terminal disposed on a top surface with at least a Zener diode and a plurality of capacitors disposed in the semiconductor substrate to couple the ground terminal to the input and output terminals with a direct capacitive coupling without an intermediate floating body region.
    Type: Application
    Filed: April 1, 2008
    Publication date: December 18, 2008
    Inventors: Moses Ho, Madhur Bobde, Mike Chang, Limin Weng