Patents by Inventor Ji Pan
Ji Pan 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).
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Patent number: 8586435Abstract: Fabricating a semiconductor device includes: forming a gate trench in an epitaxial layer overlaying a semiconductor substrate; depositing gate material in the gate trench; forming a body in the epitaxial layer; forming a source embedded in the body; forming a contact trench that extends through the source and at least part of the body; forming a body contact implant on a sidewall of the contact trench; forming a diode enhancement layer along bottom of the contact trench, the diode enhancement layer having opposite carrier type as the epitaxial layer; disposing an epitaxial enhancement portion below the diode enhancement layer, the epitaxial enhancement portion having the same carrier type as the epitaxial layer; and disposing a contact electrode in the contact trench; wherein: a distance between top surface of the substrate and bottom of the epitaxial enhancement layer is shorter than a distance between the top surface of the substrate and bottom of the body.Type: GrantFiled: December 20, 2012Date of Patent: November 19, 2013Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Ji Pan, Anup Bhalla
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Publication number: 20130280870Abstract: Fabricating a semiconductor device includes: forming a gate trench in an epitaxial layer overlaying a semiconductor substrate; depositing gate material in the gate trench; forming a body in the epitaxial layer, having a body top surface and a body bottom surface; forming a source; forming an active region contact trench that extends through the source and the body into the drain, wherein bottom surface of the active region contact trench is formed to include at least a portion that is shallower than the body bottom surface; and disposing a contact electrode within the active region contact trench.Type: ApplicationFiled: April 25, 2013Publication date: October 24, 2013Inventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
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Publication number: 20130200451Abstract: A semiconductor power device may include a lightly doped layer formed on a heavily doped layer. One or more devices are formed in the lightly doped layer. Each device may include a body region, a source region, and one or more gate electrodes formed in corresponding trenches in the lightly doped region. Each of the trenches has a depth in a first dimension, a width in a second dimension and a length in a third dimension. The body region is of opposite conductivity type to the lightly and heavily doped layers. The source region is formed proximate the upper surface. One or more deep contacts are formed at one or more locations along the third dimension proximate one or more of the trenches. The contacts extend in the first direction from the upper surface into the lightly doped layer and are in electrical contact with the source region.Type: ApplicationFiled: February 2, 2012Publication date: August 8, 2013Inventors: Hamza Yilmaz, Daniel Ng, Daniel Calafut, Madhur Bobde, Anup Bhalla, Ji Pan, Yeeheng Lee, Jongoh Kim
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Patent number: 8450794Abstract: A semiconductor device is formed on a semiconductor substrate. The device comprises a drain; an epitaxial layer overlaying the drain; a body disposed in the epitaxial layer, having a body top surface and a body bottom surface; a source embedded in the body, extending from the body top surface into the body; a first gate trench extending into the epitaxial layer; a first gate disposed in the first gate trench; an active region contact trench extending through the source and at least part of the body into the drain; an active region contact electrode disposed within the active region contact trench; a second gate trench extending into the epitaxial layer; a second gate disposed in the gate trench; a gate contact trench formed within the second gate; and a gate contact electrode disposed within the gate contact trench.Type: GrantFiled: December 9, 2011Date of Patent: May 28, 2013Assignee: Alpha & Omega Semiconductor LimitedInventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
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Patent number: 8362585Abstract: A semiconductor junction barrier Schottky (JBS-SKY) diode with enforced upper contact structure (EUCS) is disclosed. Referencing an X-Y-Z coordinate, the JBS-SKY diode has semiconductor substrate (SCST) parallel to X-Y plane. Active device zone (ACDZ) atop SCST and having a JBS-SKY diode with Z-direction current flow. Peripheral guarding zone (PRGZ) atop SCST and surrounding the ACDZ. The ACDZ has active lower semiconductor structure (ALSS) and enforced active upper contact structure (EUCS) atop ALSS. The EUC has top contact metal (TPCM) extending downwards and in electrical conduction with bottom of EUCS; and embedded bottom supporting structure (EBSS) inside TPCM and made of a hard material, the EBSS extending downwards till bottom of the EUCS. Upon encountering bonding force onto TPCM during packaging of the JBS-SKY diode, the EBSS enforces the EUCS against an otherwise potential micro cracking of the TPCM degrading the leakage current of the JBS-SKY diode.Type: GrantFiled: July 15, 2011Date of Patent: January 29, 2013Assignee: Alpha & Omega Semiconductor, Inc.Inventors: Anup Bhalla, Ji Pan, Daniel Ng
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Patent number: 8362547Abstract: A semiconductor device formed on a semiconductor substrate includes: an epitaxial layer overlaying the semiconductor substrate; a drain formed on back of the semiconductor substrate; a drain region that extends into the epitaxial layer; and an active region. The active region includes: a body disposed in the epitaxial layer, having a body top surface; a source embedded in the body, extending from the body top surface into the body; a gate trench extending into the epitaxial layer; a gate disposed in the gate trench; an active region contact trench extending through the source and the body into the drain region; an active region contact electrode disposed within the active region contact trench, wherein the active region contact electrode and the drain region form a Schottky diode; and a Schottky barrier controlling layer.Type: GrantFiled: December 21, 2007Date of Patent: January 29, 2013Assignee: Alpha & Omega Semiconductor LimitedInventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
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Patent number: 8362552Abstract: A semiconductor device includes a drain, an epitaxial layer overlaying the drain, and an active region. The active region includes a body disposed in the epitaxial layer, a source embedded in the body, a gate trench extending into the epitaxial layer, a gate disposed in the gate trench, a contact trench extending through the source and at least part of the body, a contact electrode disposed in the contact trench, and an epitaxial enhancement portion disposed below the contact trench, wherein the epitaxial enhancement portion has the same carrier type as the epitaxial layer.Type: GrantFiled: December 23, 2008Date of Patent: January 29, 2013Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Ji Pan, Anup Bhalla
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Publication number: 20130015550Abstract: A semiconductor junction barrier Schottky (JBS-SKY) diode with enforced upper contact structure (EUCS) is disclosed. Referencing an X-Y-Z coordinate, the JBS-SKY diode has semiconductor substrate (SCST) parallel to X-Y plane. Active device zone (ACDZ) atop SCST and having a JBS-SKY diode with Z-direction current flow. Peripheral guarding zone (PRGZ) atop SCST and surrounding the ACDZ. The ACDZ has active lower semiconductor structure (ALSS) and enforced active upper contact structure (EUCS) atop ALSS. The EUC has top contact metal (TPCM) extending downwards and in electrical conduction with bottom of EUCS; and embedded bottom supporting structure (EBSS) inside TPCM and made of a hard material, the EBSS extending downwards till bottom of the EUCS. Upon encountering bonding force onto TPCM during packaging of the JBS-SKY diode, the EBSS enforces the EUCS against an otherwise potential micro cracking of the TPCM degrading the leakage current of the JBS-SKY diode.Type: ApplicationFiled: July 15, 2011Publication date: January 17, 2013Inventors: Anup Bhalla, Ji Pan, Daniel Ng
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Publication number: 20130009242Abstract: A semiconductor device is formed on a semiconductor substrate. The device includes: a drain; an epitaxial layer overlaying the drain, wherein a drain region extends into the epitaxial layer; and an active region. The active region includes: a body disposed in the epitaxial layer, having a body top surface; a source embedded in the body, extending from the body top surface into the body; a gate trench extending into the epitaxial layer; a gate disposed in the gate trench; an active region contact trench extending through the source and into the body; and an active region contact electrode disposed within the active region contact trench. A layer of body region separates the active region contact electrode from the epitaxial layer, and a low injection diode is formed below a body/drain junction.Type: ApplicationFiled: September 11, 2012Publication date: January 10, 2013Applicant: ALPHA & OMEGA SEMICONDUCTOR LIMITEDInventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
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Publication number: 20130001683Abstract: A semiconductor power device comprises a plurality of power transistor cells each having a trenched gate disposed in a gate trench wherein the trenched gate comprising a shielding bottom electrode disposed in a bottom portion of the gate trench electrically insulated from a top gate electrode disposed in a top portion of the gate trench by an inter-electrode insulation layer. At least one of the transistor cells includes the shielding bottom electrode functioning as a source-connecting shielding bottom electrode electrically connected to a source electrode of the semiconductor power device and at least one of the transistor cells having the shielding bottom electrode functioning as a gate-connecting shielding bottom electrode electrically connected to a gate metal of the semiconductor power device.Type: ApplicationFiled: August 26, 2012Publication date: January 3, 2013Inventors: Ji Pan, Daniel Ng, Anup Bhalla, Xiaobin Wang
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Publication number: 20120306043Abstract: A Schottky diode includes a Schottky barrier and a plurality of dopant regions disposed near the Schottky barrier as floating islands to function as PN junctions for preventing a leakage current generated from a reverse voltage. At least a trench opened in a semiconductor substrate with a Schottky barrier material disposed therein constitutes the Schottky barrier. The Schottky barrier material may also be disposed on sidewalls of the trench for constituting the Schottky barrier. The trench may be filled with the Schottky barrier material composed of Ti/TiN or a tungsten metal disposed therein for constituting the Schottky barrier. The trench is opened in a N-type semiconductor substrate and the dopant regions includes P-doped regions disposed under the trench constitute the floating islands. The P-doped floating islands may be formed as vertical arrays under the bottom of the trench.Type: ApplicationFiled: June 27, 2012Publication date: December 6, 2012Inventors: Ji Pan, Anup Bhalla
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Patent number: 8283723Abstract: A semiconductor device is formed on a semiconductor substrate. The device includes a drain, an epitaxial layer overlaying the drain, and an active region. The active region includes a body disposed in the epitaxial layer, having a body top surface, a source embedded in the body, extending from the body top surface into the body, a gate trench extending into the epitaxial layer, a gate disposed in the gate trench, an active region contact trench extending through the source and into the body, an active region contact electrode disposed within the active region contact trench, wherein a thin layer of body region separating the active region contact electrode from the drain.Type: GrantFiled: December 21, 2007Date of Patent: October 9, 2012Assignee: Alpha & Omega Semiconductor LimitedInventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
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Patent number: 8227330Abstract: A Schottky diode includes a Schottky barrier and a plurality of dopant regions disposed near the Schottky barrier as floating islands to function as PN junctions for preventing a leakage current generated from a reverse voltage. At least a trench opened in a semiconductor substrate with a Schottky barrier material disposed therein constitutes the Schottky barrier. The Schottky barrier material may also be disposed on sidewalls of the trench for constituting the Schottky barrier. The trench may be filled with the Schottky barrier material composed of Ti/TiN or a tungsten metal disposed therein for constituting the Schottky barrier. The trench is opened in a N-type semiconductor substrate and the dopant regions includes P-doped regions disposed under the trench constitute the floating islands. The P-doped floating islands may be formed as vertical arrays under the bottom of the trench.Type: GrantFiled: February 11, 2010Date of Patent: July 24, 2012Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Ji Pan, Anup Bhalla
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Publication number: 20120080751Abstract: A semiconductor device is formed on a semiconductor substrate. The device comprises a drain; an epitaxial layer overlaying the drain; a body disposed in the epitaxial layer, having a body top surface and a body bottom surface; a source embedded in the body, extending from the body top surface into the body; a first gate trench extending into the epitaxial layer; a first gate disposed in the first gate trench; an active region contact trench extending through the source and at least part of the body into the drain; an active region contact electrode disposed within the active region contact trench; a second gate trench extending into the epitaxial layer; a second gate disposed in the gate trench; a gate contact trench formed within the second gate; and a gate contact electrode disposed within the gate contact trench.Type: ApplicationFiled: December 9, 2011Publication date: April 5, 2012Applicant: ALPHA & OMEGA SEMICONDUCTOR LIMITEDInventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
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Publication number: 20120068262Abstract: A MOSFET device and fabrication method are disclosed. The MOSFET has a drain in chip plane with an epitaxial layer overlay atop. The MOSFET further comprises: a Kelvin-contact body and an embedded Kelvin-contact source; a trench gate extending into the epitaxial layer; a lower contact trench extending through the Kelvin-contact source and at least part of the Kelvin-contact body defining respectively a vertical source-contact surface and a vertical body-contact surface; a patterned dielectric layer atop the Kelvin-contact source and the trench gate; a patterned top metal layer. As a result: a planar ledge is formed atop the Kelvin-contact source; the MOSFET device exhibits a lowered body Kelvin contact impedance and, owing to the presence of the planar ledge, a source Kelvin contact impedance that is lower than an otherwise MOSFET device without the planar ledge; and an integral parallel Schottky diode is also formed.Type: ApplicationFiled: November 29, 2011Publication date: March 22, 2012Inventor: Ji Pan
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Patent number: 8093651Abstract: A semiconductor device is formed on a semiconductor substrate. The device comprises a drain, an epitaxial layer overlaying the drain, and an active region. The active region comprises a body disposed in the epitaxial layer, having a body top surface and a body bottom surface, a source embedded in the body, extending from the body top surface into the body, a gate trench extending into the epitaxial layer, a gate disposed in the gate trench, an active region contact trench extending through the source and at least part of the body into the drain, wherein the active region contact trench is shallower than the body bottom surface, and an active region contact electrode disposed within the active region contact trench.Type: GrantFiled: December 21, 2007Date of Patent: January 10, 2012Assignee: Alpha & Omega Semiconductor LimitedInventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
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Patent number: 8053808Abstract: A semiconductor power device supported on a semiconductor substrate includes a plurality of transistor cells each having a source and a drain with a gate to control an electric current transmitted between the source and the drain. The semiconductor further includes a source metal connected to the source region, and a gate metal configured as a metal stripe surrounding a peripheral region of the substrate connected to a gate pad wherein the gate metal and the gate pad are separated from the source metal by a metal gap. The semiconductor power device further includes an ESD protection circuit includes a plurality of doped polysilicon regions of opposite conductivity types constituting ESD diodes extending across the metal gap and connected between the gate metal and the source metal on the peripheral region of the substrate.Type: GrantFiled: May 21, 2007Date of Patent: November 8, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Yi Su, Anup Bhalla, Daniel Ng, Wei Wang, Ji Pan
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Publication number: 20110042727Abstract: A semiconductor device includes a drain, an epitaxial layer overlaying the drain, and an active region. The active region includes a body disposed in the epitaxial layer, a source embedded in the body, a gate trench extending into the epitaxial layer, a gate disposed in the gate trench, a contact trench extending through the source and at least part of the body, a contact electrode disposed in the contact trench, and an epitaxial enhancement portion disposed below the contact trench, wherein the epitaxial enhancement portion has the same carrier type as the epitaxial layer.Type: ApplicationFiled: December 23, 2008Publication date: February 24, 2011Inventors: Ji Pan, Anup Bhalla
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Publication number: 20100155876Abstract: A Schottky diode includes a Schottky barrier and a plurality of dopant regions disposed near the Schottky barrier as floating islands to function as PN junctions for preventing a leakage current generated from a reverse voltage. At least a trench opened in a semiconductor substrate with a Schottky barrier material disposed therein constitutes the Schottky barrier. The Schottky barrier material may also be disposed on sidewalls of the trench for constituting the Schottky barrier. The trench may be filled with the Schottky barrier material composed of Ti/TiN or a tungsten metal disposed therein for constituting the Schottky barrier. The trench is opened in a N-type semiconductor substrate and the dopant regions includes P-doped regions disposed under the trench constitute the floating islands. The P-doped floating islands may be formed as vertical arrays under the bottom of the trench.Type: ApplicationFiled: February 11, 2010Publication date: June 24, 2010Inventors: Ji Pan, Anup Bhalla
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Patent number: 7671439Abstract: A Schottky diode includes a Schottky barrier and a plurality of dopant regions disposed near the Schottky barrier as floating islands to function as PN junctions for preventing a leakage current generated from a reverse voltage. At least a trench opened in a semiconductor substrate with a Schottky barrier material disposed therein constitutes the Schottky barrier. The Schottky barrier material may also be disposed on sidewalls of the trench for constituting the Schottky barrier. The trench may be filled with the Schottky barrier material composed of Ti/TiN or a tungsten metal disposed therein for constituting the Schottky barrier. The trench is opened in a N-type semiconductor substrate and the dopant regions includes P-doped regions disposed under the trench constitute the floating islands. The P-doped floating islands may be formed as vertical arrays under the bottom of the trench.Type: GrantFiled: December 1, 2006Date of Patent: March 2, 2010Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Ji Pan, Anup Bhalla