Patents by Inventor Tiesheng Li

Tiesheng Li 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: 8735973
    Abstract: The embodiments of the present disclosure disclose a trench-gate MOSFET device and the method for making the trench-gate MOSFET device. The trench-gate MOSFET device comprises a curving dopant profile formed between the body region and the epitaxial layer so that the portion of the body region under the source metal contact has a smaller vertical thickness than the other portion of the body region. The trench-gate MOSFET device in accordance with the embodiments of the present disclosure has improved UIS capability compared with the traditional trench-gate MOSFET device.
    Type: Grant
    Filed: May 2, 2012
    Date of Patent: May 27, 2014
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Lei Zhang, Donald Ray Disney, Tiesheng Li, Rongyao Ma
  • Patent number: 8735968
    Abstract: The present technology discloses a semiconductor die integrating a MOSFET device and a Schottky diode. The semiconductor die comprises a MOSFET area comprising the active region of MOSFET, a Schottky diode area comprising the active region of Schottky diode, and a termination area comprising termination structures. Wherein the Schottky diode area is placed between the MOSFET area and the termination area such that the Schottky diode area surrounds the MOSFET area.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: May 27, 2014
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Tiesheng Li, Lei Zhang
  • Patent number: 8723178
    Abstract: An integrated circuit includes a junction field effect transistor (JFET) and a power metal oxide semiconductor field effect transistor (MOSFET) on a same substrate. The integrated circuit includes a drain sense terminal for sensing the drain of the power MOSFET through the JFET. The JFET protects a controller or other electrical circuit coupled to the drain sense terminal from high voltage that may be present on the drain of the power MOSFET. The JFET and the power MOSFET share a same drift region, which includes an epitaxial layer formed on the substrate. The integrated circuit may be packaged in a four terminal small outline integrated circuit (SOIC) package. The integrated circuit may be employed in a variety of applications including as an ideal diode.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: May 13, 2014
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Tiesheng Li
  • Patent number: 8716784
    Abstract: A semiconductor device and a method for forming the semiconductor device wherein the semiconductor comprises: a trench MOSFET, formed on a semiconductor initial layer, comprising a well region, wherein the semiconductor initial layer has a first conductivity type and wherein the well region has a second conductivity type; an integrated Schottky diode next to the trench MOSFET, comprising a anode metal layer contacted to the semiconductor initial layer; a trench isolation structure, coupled between the trench MOSFET and integrated Schottky diode, configured to resist part of lateral diffusion from the well region; wherein the well region comprises an overgrowth part which laterally diffuses under the trench isolation structure and extends out of it.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: May 6, 2014
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Lei Zhang, Tiesheng Li
  • Publication number: 20140117416
    Abstract: A semiconductor device having a trench-gate MOSFET and a vertical JFET formed in a semiconductor layer. In the semiconductor device, a gate region of the vertical JFET may be electrically coupled to a source region of the trench-gate MOSFET, and a drain region of the vertical JFET and a drain region of the trench-gate MOSFET may share a common region in the semiconductor layer.
    Type: Application
    Filed: October 31, 2013
    Publication date: May 1, 2014
    Inventors: Lei Zhang, Tiesheng Li, Rongyao Ma, Daping Fu
  • Publication number: 20140117415
    Abstract: A JFET having a semiconductor substrate of a first doping type, an epitaxial layer of the first doping type located on the semiconductor substrate, a body region of a second doping type located in the epitaxial layer, a source region of the first doping type located in the epitaxial layer, a gate region of the second doping type located in the body region, and a shielding layer of the second doping type located in the epitaxial layer, wherein the semiconductor substrate is configured as a drain region, the shielding layer is in a conductive path formed between the source region and the drain region.
    Type: Application
    Filed: October 29, 2013
    Publication date: May 1, 2014
    Applicant: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Rongyao Ma, Tiesheng Li, Lei Zhang, Daping Fu
  • Publication number: 20140103416
    Abstract: A semiconductor device having an ESD protection structure and a method for forming the semiconductor device. The semiconductor device further includes a semiconductor transistor formed in an active cell area of a substrate. The ESD protection structure is formed atop a termination area of the substrate and is of solid closed shape. The ESD protection structure includes a central doped zone of a first conductivity type and a plurality of second-conductivity-type doped zones and first-conductivity-type doped zones alternately disposed surrounding the central doped zone. The central doped zone occupies substantially the entire portion of the ESD protection structure that is overlapped by a gate metal pad, and is electrically coupled to the gate metal pad. The outmost first-conductivity-type doped zone is electrically coupled to a source metal. The ESD protection structure features a reduced resistance and an improved current uniformity and provides enhanced ESD protection to the transistor.
    Type: Application
    Filed: October 10, 2013
    Publication date: April 17, 2014
    Applicant: CHENGDU MONOLITHIC POWER SYSTEMS CO., LTD.
    Inventors: Rongyao Ma, Tiesheng Li, Huaifeng Wang, Heng Li, Fayou Yin
  • Patent number: 8680614
    Abstract: A split trench-gate MOSFET device and method for forming this device is disclosed. The device has a trench gate structure, comprising a shield electrode and two gate electrodes, wherein a substantial portion of shield electrode region is lower than the gate electrode region, and wherein a portion of the shield electrode region extends to the top surface between the two gate electrodes. The device further comprises a source metal layer, contacting to an initial layer, a well region, the shield electrode and a source region at the top surface, wherein the contact between the source metal layer and the initial layer forms a Schottky diode.
    Type: Grant
    Filed: June 12, 2012
    Date of Patent: March 25, 2014
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Tiesheng Li, Rongyao Ma, Lei Zhang
  • Publication number: 20130328122
    Abstract: A split trench-gate MOSFET device and method for forming this device is disclosed. The device has a trench gate structure, comprising a shield electrode and two gate electrodes, wherein a substantial portion of shield electrode region is lower than the gate electrode region, and wherein a portion of the shield electrode region extends to the top surface between the two gate electrodes. The device further comprises a source metal layer, contacting to an initial layer, a well region, the shield electrode and a source region at the top surface, wherein the contact between the source metal layer and the initial layer forms a Schottky diode.
    Type: Application
    Filed: June 12, 2012
    Publication date: December 12, 2013
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Tiesheng Li, Rongyao Ma, Lei Zhang
  • Patent number: 8597998
    Abstract: Fabricating a semiconductor device includes forming a mask on a substrate having a top substrate surface; forming a gate trench in the substrate, through the mask; depositing gate material in the gate trench; removing the mask to leave a gate structure; implanting a body region; implanting a source region; forming a source body contact trench having a trench wall and a trench bottom; forming a plug in the source body contact trench, wherein the plug extends below a bottom of the body region; and disposing conductive material in the source body contact trench, on top of the plug.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: December 3, 2013
    Assignee: Alpha & Omega Semiconductor Limited
    Inventors: Anup Bhalla, Sik K. Lui, Tiesheng Li
  • Patent number: 8546879
    Abstract: The present disclosure discloses a lateral DMOS with recessed source contact and method for making the same. The lateral DMOS comprises a recessed source contact which has a portion recessed into a source region to reach a body region of the lateral DMOS. The lateral DMOS according to various embodiments of the present invention may have greatly reduced size and may be cost saving for fabrication.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: October 1, 2013
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Donald R. Disney, Lei Zhang, Tiesheng Li
  • Publication number: 20130234245
    Abstract: A super junction structural semiconductor device with a substantially rectangle-shaped first region, and a second region surrounding the periphery of the first region; trench gate MOSFET units in the first region comprising a plurality of trench gate regions and a first plurality of pillars; a body region between the trench gate regions and the first plurality of pillars; a second plurality of pillars in the second region extending along a corresponding side of the first region comprising a plurality of lateral pillars and a plurality of longitudinal pillars, wherein in a corner part of the second region, ends of the plurality of lateral pillars and ends of the plurality of longitudinal pillars are stagger and separated apart from each other.
    Type: Application
    Filed: March 6, 2013
    Publication date: September 12, 2013
    Applicant: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Rongyao Ma, Tiesheng Li, Donald Disney, Lei Zhang
  • Patent number: 8525260
    Abstract: RESURF effect devices with both relatively deep trenches and relatively deep implants are described herein. Also, methods of fabricating such devices are described herein. A RESURF effect device may include alternating regions of first and second conductivity types where each of the second regions includes an implant region formed into a trench region of the second region.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: September 3, 2013
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Tiesheng Li, Michael R. Hsing, Deming Xiao
  • Publication number: 20130187160
    Abstract: An integrated circuit includes a junction field effect transistor (JFET) and a power metal oxide semiconductor field effect transistor (MOSFET) on a same substrate. The integrated circuit includes a drain sense terminal for sensing the drain of the power MOSFET through the JFET. The JFET protects a controller or other electrical circuit coupled to the drain sense terminal from high voltage that may be present on the drain of the power MOSFET. The JFET and the power MOSFET share a same drift region, which includes an epitaxial layer formed on the substrate. The integrated circuit may be packaged in a four terminal small outline integrated circuit (SOIC) package. The integrated circuit may be employed in a variety of applications including as an ideal diode.
    Type: Application
    Filed: January 20, 2012
    Publication date: July 25, 2013
    Inventor: Tiesheng LI
  • Patent number: 8471368
    Abstract: This invention discloses a semiconductor wafer for manufacturing electronic circuit thereon. The semiconductor substrate further includes an etch-back indicator that includes trenches of different sizes having polysilicon filled in the trenches and then completely removed from some of the trenches of greater planar trench dimensions and the polysilicon still remaining in a bottom portion in some of the trenches having smaller planar trench dimensions.
    Type: Grant
    Filed: March 27, 2012
    Date of Patent: June 25, 2013
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yu Wang, Tiesheng Li, Sung-Shan Tai, Hong Chang
  • Publication number: 20130153999
    Abstract: A trench gate MOSFET device has a drain region, a drift region, a trench gate having a gate electrode and a poly-silicon region, a super junction pillar juxtaposing the trench gate, a body region and a source region. By the interaction among the trench gate, the drift region and the super junction pillar, the break down voltage of the trench gate MOSFET device may be relatively high while the on-state resistance of the trench gate MOSFET device may be maintained relatively small.
    Type: Application
    Filed: December 20, 2012
    Publication date: June 20, 2013
    Inventors: Lei Zhang, Donald Disney, Tiesheng Li, Rongyao Ma
  • Publication number: 20130093001
    Abstract: This invention discloses a new switching device that includes a drain disposed on a first surface and a source region disposed near a second surface of a semiconductor opposite the first surface. An insulated gate electrode is disposed on top of the second surface for controlling a source to drain current and a source electrode is interposed into the insulated gate electrode for substantially preventing a coupling of an electrical field between the gate electrode and an epitaxial region underneath the insulated gate electrode. The source electrode further covers and extends over the insulated gate for covering an area on the second surface of the semiconductor to contact the source region, An epitaxial layer is disposed above and having a different dopant concentration than the drain region. The gate electrode is insulated from the source electrode by an insulation layer having a thickness depending on a Vgsmax rating of the vertical power device.
    Type: Application
    Filed: March 30, 2012
    Publication date: April 18, 2013
    Inventors: Anup Bhalla, Daniel Ng, Tiesheng Li, Sik K. Lui
  • Publication number: 20130043534
    Abstract: The present disclosure discloses a lateral DMOS with recessed source contact and method for making the same. The lateral DMOS comprises a recessed source contact which has a portion recessed into a source region to reach a body region of the lateral DMOS. The lateral DMOS according to various embodiments of the present invention may have greatly reduced size and may be cost saving for fabrication.
    Type: Application
    Filed: August 18, 2011
    Publication date: February 21, 2013
    Inventors: Donald R. Disney, Lei Zhang, Tiesheng Li
  • Publication number: 20120329225
    Abstract: Fabricating a semiconductor device includes forming a mask on a substrate having a top substrate surface; forming a gate trench in the substrate, through the mask; depositing gate material in the gate trench; removing the mask to leave a gate structure; implanting a body region; implanting a source region; forming a source body contact trench having a trench wall and a trench bottom; forming a plug in the source body contact trench, wherein the plug extends below a bottom of the body region; and disposing conductive material in the source body contact trench, on top of the plug.
    Type: Application
    Filed: September 5, 2012
    Publication date: December 27, 2012
    Applicant: ALPHA & OMEGA SEMICONDUCTOR LIMITED
    Inventors: Anup Bhalla, Sik Lui, Tiesheng Li
  • Publication number: 20120280311
    Abstract: The embodiments of the present disclosure disclose a trench-gate MOSFET device and the method for making the trench-gate MOSFET device. The trench-gate MOSFET device comprises a curving dopant profile formed between the body region and the epitaxial layer so that the portion of the body region under the source metal contact has a smaller vertical thickness than the other portion of the body region. The trench-gate MOSFET device in accordance with the embodiments of the present disclosure has improved UIS capability compared with the traditional trench-gate MOSFET device.
    Type: Application
    Filed: May 2, 2012
    Publication date: November 8, 2012
    Applicant: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Lei Zhang, Donald R. Disney, Tiesheng Li, Rongyao Ma