With Electric Field Controlling Semiconductor Layer Having A Low Enough Doping Level In Relationship To Its Thickness To Be Fully Depleted Prior To Avalanche Breakdown (e.g., Resurf Devices) Patents (Class 257/492)
  • Patent number: 8350338
    Abstract: A semiconductor device is disclosed. In an embodiment, a semiconductor device includes a N-well within a P-well in a silicon layer, the silicon layer positioned atop a buried oxide layer of a silicon-on-insulator (SOI) substrate; a first source region and a second source region within a portion of the P-well; a first drain region and a second drain region within a portion of the P-well and within a portion of the N-well; and a gate positioned atop the N-well, wherein a lateral high field region is generated between the N-well and the P-well and a vertical high field region is generated between the gate and the N-well. A related method is disclosed.
    Type: Grant
    Filed: February 8, 2011
    Date of Patent: January 8, 2013
    Assignee: International Business Machines Corporations
    Inventors: William F. Clark, Jr., Yun Shi
  • Patent number: 8344472
    Abstract: Transistors (21, 41) employing floating buried layers may be susceptible to noise coupling into the floating buried layers. In IGFETS this is reduced or eliminated by providing a normally-ON switch (80, 80?) coupling the buried layer (102, 142, 172, 202) and the IGFET source (22, 42) or drain (24, 44). When the transistor (71, 91) is OFF, this clamps the buried layer voltage and substantially prevents noise coupling thereto. When the drain-source voltage VDS exceeds the switch's (80, 80?) threshold voltage Vt, it turns OFF, allowing the buried layer (102, 142, 172, 202) to float, and thereby resume normal transistor action without degrading the breakdown voltage or ON-resistance. In a preferred embodiment, a normally-ON lateral JFET (801, 801?, 801-1, 801-2, 801-3) conveniently provides this switching function.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: January 1, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu K. Khemka, Tahir A. Khan, Weixiao Huang, Ronghua Zhu
  • Patent number: 8330233
    Abstract: A semiconductor device 1 including a cell region 2 formed with a semiconductor element 6 and a periphery region 3 formed in the periphery of the cell region 2. The semiconductor region 1 is arranged with an n? type drift region 12 formed in the cell region 2 and periphery region 3, a plurality of p? type columnar regions formed in the n? drift region 12 of the cell region 2, a plurality of p? type columnar resistance improvement regions 23n formed in the n? type drift region 12 of the periphery region 3, and a plurality of electrical field buffer regions 24n formed in an upper part of the p? type columnar region 23n. An interval Sn between the electrical field buffer region 24n and an adjacent electrical field buffer region 24n is different between an interior side and an exterior side of the periphery region 3.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: December 11, 2012
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Tomoyuki Omori
  • Patent number: 8330213
    Abstract: Power devices using refilled trenches with permanent charge at or near their sidewalls. These trenches extend vertically into a drift region.
    Type: Grant
    Filed: April 13, 2010
    Date of Patent: December 11, 2012
    Assignee: MaxPower Semiconductor, Inc.
    Inventors: Mohamed N. Darwish, Jun Zeng, Richard A. Blanchard
  • Patent number: 8274129
    Abstract: A method includes forming a transistor device on a first side of a semiconductor-on-insulator structure. The semiconductor-on-insulator structure includes a substrate, a dielectric layer, and a buried layer between the substrate and the dielectric layer. The method also includes forming a conductive plug through the semiconductor-on-insulator structure. The conductive plug is in electrical connection with the transistor device. The method further includes forming a field plate on a second side of the semiconductor-on-insulator structure, where the field plate is in electrical connection with the conductive plug. The transistor device could have a breakdown voltage of at least 600V, and the field plate could extend along at least 40% of a length of the transistor device.
    Type: Grant
    Filed: October 23, 2009
    Date of Patent: September 25, 2012
    Assignee: National Semiconductor Corporation
    Inventors: William French, Peter Smeys, Peter J. Hopper, Peter Johnson
  • Patent number: 8269270
    Abstract: A vertical semiconductor component having a semiconductor body, which has an inner region and an edge region that is arranged between the inner region and an edge of the semiconductor body. At least one semiconductor junction between a first semiconductor zone of a first conduction type, said first semiconductor zone being arranged in the region of a first side of the semiconductor body in the inner region, and a second semiconductor zone of the second conduction type, said second semiconductor zone adjoining the first semiconductor zone in the vertical direction.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: September 18, 2012
    Assignee: Infineon Technologies AG
    Inventors: Anton Mauder, Hans-Joachim Schulze
  • Patent number: 8242572
    Abstract: A semiconductor apparatus includes, below a high-voltage wiring, a p? diffusion layer in contact with an n drain buffer layer and a p+ diffusion layer in contact with a p? diffusion layer for reducing the electric field strength in an insulator film, which the high-voltage wiring crosses over. Reducing electric field strength in the insulator film prevents lowering of breakdown voltage of a high-voltage NMOSFET, break down of an interlayer insulator film, and impairment of isolation breakdown voltage of a device isolation trench. The semiconductor apparatus according to the invention facilitates bridging a high-voltage wiring from a high-voltage NMOSFET and such a level-shifting device to a high-voltage floating region crossing over a device isolation trench without impairing the breakdown voltage of the high-voltage NMOSFET, without breaking down the interlayer insulator film and without impairing the isolation breakdown voltage of the device isolation trench.
    Type: Grant
    Filed: November 2, 2010
    Date of Patent: August 14, 2012
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Masaharu Yamaji
  • Patent number: 8227868
    Abstract: A semiconductor device according to the present invention includes a semiconductor substrate of a first conductivity type having a top surface and a rear surface, a semiconductor layer of a second conductivity type formed on the top surface of the semiconductor substrate, having a top surface and a rear surface, and having the rear surface in contact with the top surface of the semiconductor substrate, a body region of the first conductivity type formed in a top layer portion of the semiconductor layer, a first impurity region of the second conductivity type formed in a top layer portion of the semiconductor layer and spaced apart from the body region, a second impurity region of the second conductivity type formed in a top layer portion of the body region and spaced apart from a peripheral edge of the body region, a gate electrode formed on the semiconductor layer and opposed to a portion between the peripheral edge of the body region and a peripheral edge of the second impurity region, a field insulating fi
    Type: Grant
    Filed: January 31, 2011
    Date of Patent: July 24, 2012
    Assignee: Rohm Co., Ltd.
    Inventor: Daisuke Ichikawa
  • Patent number: 8212329
    Abstract: A short channel Lateral MOSFET (LMOS) and method are disclosed with interpenetrating drain-body protrusions (IDBP) for reducing channel-on resistance while maintaining high punch-through voltage. The LMOS includes lower device bulk layer; upper source and upper drain region both located atop lower device bulk layer; both upper source and upper drain region are in contact with an intervening upper body region atop lower device bulk layer; both upper drain and upper body region are shaped to form a drain-body interface; the drain-body interface has an IDBP structure with a surface drain protrusion lying atop a buried body protrusion while revealing a top body surface area of the upper body region; gate oxide-gate electrode bi-layer disposed atop the upper body region forming an LMOS with a short channel length defined by the horizontal length of the top body surface area delineated between the upper source region and the upper drain region.
    Type: Grant
    Filed: November 6, 2010
    Date of Patent: July 3, 2012
    Assignee: Alpha and Omega Semiconductor Inc.
    Inventors: Shekar Mallikarjunaswamy, Amit Paul
  • Patent number: 8198154
    Abstract: Lateral DMOS devices having improved drain contact structures and methods for making the devices are disclosed. A semiconductor device comprises a semiconductor substrate; an epitaxial layer on top of the substrate; a drift region at a top surface of the epitaxial layer; a source region at a top surface of the epitaxial layer; a channel region between the source and drift regions; a gate positioned over a gate dielectric on top of the channel region; and a drain contact trench that electrically connects the drift layer and substrate. The contact trench includes a trench formed vertically from the drift region, through the epitaxial layer to the substrate and filled with an electrically conductive drain plug; electrically insulating spacers along sidewalls of the trench; and an electrically conductive drain strap on top of the drain contact trench that electrically connects the drain contact trench to the drift region.
    Type: Grant
    Filed: September 27, 2010
    Date of Patent: June 12, 2012
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: François Hébert
  • Publication number: 20120104492
    Abstract: The present invention relates to a low on-resistance RESURF MOS transistor, comprising: a drift region; two isolation regions formed on the drift region; a first-doping-type layer disposed between the two isolation regions; and a second-doping-type layer disposed below the first-doping-type layer.
    Type: Application
    Filed: October 29, 2010
    Publication date: May 3, 2012
    Applicant: MACRONIX INTERNATIONAL CO., LTD.
    Inventors: Chien-Wen CHU, Wing-Chor CHAN, Shyi-Yuan WU
  • Patent number: 8148758
    Abstract: A high-voltage field-effect device contains an extended drain or “drift” region including an embedded stack of JFET regions separated by intervening layers of the drift region. Each of the JFET regions is filled with material of an opposite conductivity type to that of the drift region, and the floor and ceiling of each JFET region is lined with an oxide layer. When the device is blocking a voltage in the off condition, the semiconductor material inside the JFET regions and in the drift region that separates the JFET regions is depleted. This improves the voltage-blocking ability of the device while conserving chip area. The oxide layer prevents dopant from the JFET regions from diffusing into the drift region.
    Type: Grant
    Filed: December 16, 2010
    Date of Patent: April 3, 2012
    Assignee: Alpha and Omega Semiconductor Inc.
    Inventor: Hamza Yilmaz
  • Patent number: 8148778
    Abstract: A semiconductor device includes: an n-type first well diffusion layer; an n-type second well diffusion layer; a p-type source diffusion layer; a p-type third well diffusion layer; a p-type drain diffusion layer; a gate insulating film; a gate electrode; a device isolation insulating film; and a buffer layer. The buffer layer is formed between the first well diffusion layer and the third well diffusion layer to be in contact with an end of the third well diffusion layer opposing the source diffusion layer, and extends from immediately below the gate insulating film to a position deeper than a peak of curvature of impurity concentration distribution of the third well diffusion layer. The buffer layer has an impurity concentration lower than an impurity concentration in the third well diffusion layer.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: April 3, 2012
    Assignee: Panasonic Corporation
    Inventors: Yasushi Kobayashi, Manabu Imahashi
  • Patent number: 8143691
    Abstract: To provide a semiconductor device and a method of making the same, the device being capable of preventing decrease in the withstanding voltage along the direction perpendicular to the source-drain direction and thereby improving the resistance to an overvoltage (overcurrent), the device includes: a p-type semiconductor substrate 201; an n-type diffusion region 202; a p-type body region 206, a p-type buried diffusion region 204, and an n-type drift region 207 within the n-type diffusion region 202; an n-type source region 208 and a p-type body contact region 209 within the p-type body region 206; an n-type drain region 210 within the n-type drift region 207; a gate insulating film above the p-type body region 206; and a gate electrode 211 above the gate insulating film, where the region 204 extends away from the region 206 farther than the farther edge of the gate electrode 211 is along a cross section perpendicular to the source-drain direction.
    Type: Grant
    Filed: September 10, 2009
    Date of Patent: March 27, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Hisao Ichijo
  • Patent number: 8138570
    Abstract: An isolation structure for a semiconductor device comprises a floor isolation region, a dielectric filled trench above the floor isolation region and a sidewall isolation region extending downward from the bottom of the trench to the floor isolation region. This structure provides a relatively deep isolated pocket in a semiconductor substrate while limiting the depth of the trench that must be etched in the substrate. An isolated junction field-effect transistor is formed in the isolated pocket.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: March 20, 2012
    Assignees: Advanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) Limited
    Inventors: Richard K. Williams, Donald Ray Disney, Wai Tien Chan
  • Patent number: 8106454
    Abstract: A vertical power semiconductor device includes a first semiconductor layer of a first conductivity type formed in both a cell section and a termination section, the termination section surrounding the cell section, a second semiconductor layer of a second conductivity type formed on the first semiconductor layer in the cell section, a third semiconductor layer of the first conductivity type formed in part on the second semiconductor layer, and a guard ring layer of the second conductivity type formed on the first semiconductor layer in the termination section. Net impurity concentration in the guard ring layer is generally sloped so as to be relatively high on its lower side and relatively low on its upper side. Alternatively, the net impurity concentration in the guard ring layer is constant.
    Type: Grant
    Filed: November 6, 2008
    Date of Patent: January 31, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Miwako Akiyama, Yusuke Kawaguchi, Yoshihiro Yamaguchi
  • Patent number: 8097919
    Abstract: An electronic device includes a drift layer having a first conductivity type, a buffer layer having a second conductivity type, opposite the first conductivity type, on the drift layer and forming a P?N junction with the drift layer, and a junction termination extension region having the second conductivity type in the drift layer adjacent the P?N junction. The buffer layer includes a step portion that extends over a buried portion of the junction termination extension. Related methods are also disclosed.
    Type: Grant
    Filed: August 11, 2008
    Date of Patent: January 17, 2012
    Assignee: Cree, Inc.
    Inventors: Qingchun Zhang, Anant K. Agarwal
  • Patent number: 8080858
    Abstract: A Semiconductor component having a space saving edge structure is disclosed. One embodiment provides a first side, a second side, an inner region, an edge region adjoining the inner region in a lateral direction of the semiconductor body, and a first semiconductor layer extending across the inner region and the edge region and having a basic doping of a first conductivity type. At least one active component zone of a second conductivity type, which is complementary to the first conductivity type, is disposed in the inner region in the first semiconductor layer. An edge structure is disposed in the edge region and includes at least one trench extending from the first side into the semiconductor body. An edge electrode is disposed in the trench, a dielectric layer is disposed in the trench between the edge electrode and the semiconductor body, a first edge zone of the second conductivity type adjoin the trench and are at least partially disposed below the trench.
    Type: Grant
    Filed: August 3, 2007
    Date of Patent: December 20, 2011
    Assignee: Infineon Technologies Austria AG
    Inventors: Franz Hirler, Ralf Siemieniec, Christian Geissler
  • Patent number: 8053859
    Abstract: To provide a semiconductor device that exhibits a high breakdown voltage, excellent thermal properties, a high latch-up withstanding capability and low on-resistance. The semiconductor device according to the invention, which includes a buried insulator region 5 disposed between an n?-type drift layer 3 and a first n-type region 7 above n?-type drift layer 3, facilitates limiting the emitter hole current, preventing latch-up from occurring, raising neither on-resistance nor on-voltage. The semiconductor device according to the invention, which includes a p-type region 4 disposed between the buried insulator region 5 and n?-type drift layer 3, facilitates depleting n?-type drift layer 3 in the OFF-state of the device.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: November 8, 2011
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Hong-fei Lu, Shinichi Jimbo
  • Patent number: 8034700
    Abstract: A method of fabricating a diode is disclosed. One embodiment provides a semiconductor body having a front and a back, opposite the front in a vertical direction of the semiconductor body. The semiconductor body contains, successively in the vertical direction from the back to the front, a heavily n-doped zone, a weakly n-doped zone, a weakly p-doped zone and a heavily p-doped zone. In the vertical direction, the weakly p-doped zone has a thickness of at least 25% and at most 50% of the thickness of the semiconductor body.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: October 11, 2011
    Assignee: Infineon Technologies AG
    Inventors: Hans-Joachim Schulze, Franz-Josef Niedernostheide, Reiner Barthelmess
  • Patent number: 7999312
    Abstract: A semiconductor 100 has a P? body region and an N? drift region in the order from an upper surface side thereof. A gate trench and a terminal trench passing through the P? body region are formed. The respective trenches are surrounded with P diffusion regions at the bottom thereof. The gate trench builds a gate electrode therein. A P?? diffusion region, which is in contact with the end portion in a lengthwise direction of the gate trench and is lower in concentration than the P? body region and the P diffusion region, is formed. The P?? diffusion region is depleted prior to the P diffusion region when the gate voltage is off. The P?? diffusion region serves as a hole supply path to the P diffusion region when the gate voltage is on.
    Type: Grant
    Filed: January 26, 2007
    Date of Patent: August 16, 2011
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hidefumi Takaya, Kimimori Hamada, Kyosuke Miyagi
  • Patent number: 7989910
    Abstract: A semiconductor device includes an n+ type semiconductor substrate 1 and a super junction region that has, on the top of the substrate 1, an n and p type pillar regions 2 and 3 provided alternately. The device also includes, in the top surface of the super junction region, a p type base region 4 and an n type source layer 5. The device also includes a gate electrode 7 on the region 4 and layer 5 via a gate-insulating film 6, a drain electrode 9 on the bottom of the substrate 1, and a source electrode 8 on the top of the substrate 1. In the top surface of the super junction region in the terminal region, a RESURF region 10 is formed. The RESURF region has a comb-like planar shape with repeatedly-formed teeth having tips facing the end portion of the terminal region.
    Type: Grant
    Filed: October 16, 2008
    Date of Patent: August 2, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Syotaro Ono, Masaru Izumisawa, Yasuto Sumi, Hiroshi Ohta, Wataru Sekine, Nana Hatano
  • Patent number: 7973382
    Abstract: A gate electrode 20 and first field plates 22a to 22d and 23 are provided on a field oxide film 19. The gate electrode 20 and first field plates 22a to 22d and 23 are covered with an insulating film 24. A high-voltage wiring conductor 28 is provided on the insulating film 24. A shielding electrode 29 is provided between the first field plate 22a positioned closest to a source side and the high-voltage wiring conductor 28.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: July 5, 2011
    Assignee: Mitsubishi Electric Corporation
    Inventor: Tetsuo Takahashi
  • Patent number: 7964931
    Abstract: A semiconductor device 1 includes a square substrate 2, first RESURF structures 3 in the shape of planar stripes on an element area 10 of a main surface of the substrate 2, a transistor T arranged between the first RESURF structures 3, a first high withstand voltage section 11 constituted by second RESURF structures 3a in the shape of planar strips on a periphery of the main surface of the substrate 2, and a second high withstand voltage section 12 constituted by third RESURF structures 3b which are symmetrically arranged at corners of the substrate 2 with respect to a diagonal line D of the main surface of the substrate 2.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: June 21, 2011
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Hironori Aoki
  • Patent number: 7948040
    Abstract: A semiconductor device includes a semiconductor layer overlapping with a gate electrode and having an impurity region outside a region which overlaps with the gate electrode; a first conductive layer which is provided on a side provided with the gate electrode of the semiconductor layer and partially in contact with the impurity region; an insulating layer provided over the gate electrode and the first conductive layer; and a second conductive layer which is formed in the insulating layer and in contact with the first conductive layer through an opening at least part of which overlaps with the first conductive layer.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: May 24, 2011
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Kengo Akimoto
  • Patent number: 7944035
    Abstract: A semiconductor die has devices such as MOSgated devices, diodes and the like formed into the top and bottom surfaces of the die. One terminal of each of the devices terminal in the interior center of the die and a common contact is made to the interior center of the die at one edge of the die. Various packages for the die having a reduced foot print on a support substrate are disclosed.
    Type: Grant
    Filed: May 16, 2007
    Date of Patent: May 17, 2011
    Assignee: International Rectifier Corporation
    Inventor: Igor Bol
  • Patent number: 7932558
    Abstract: A semiconductor device includes: an n-type first well diffusion layer; an n-type second well diffusion layer; a p-type source diffusion layer; a p-type third well diffusion layer; a p-type drain diffusion layer; a gate insulating film; a gate electrode; a device isolation insulating film; and a buffer layer. The buffer layer is formed between the first well diffusion layer and the third well diffusion layer to be in contact with an end of the third well diffusion layer opposing the source diffusion layer, and extends from immediately below the gate insulating film to a position deeper than a peak of curvature of impurity concentration distribution of the third well diffusion layer. The buffer layer has an impurity concentration lower than an impurity concentration in the third well diffusion layer.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: April 26, 2011
    Assignee: Panasonic Corporation
    Inventors: Yasushi Kobayashi, Manabu Imahashi
  • Patent number: 7915705
    Abstract: A SiC semiconductor device includes: a SiC substrate; a SiC drift layer on the substrate having an impurity concentration lower than the substrate; a semiconductor element in a cell region of the drift layer; an outer periphery structure including a RESURF layer in a surface portion of the drift layer and surrounding the cell region; and an electric field relaxation layer in another surface portion of the drift layer so that the electric field relaxation layer is separated from the RESURF layer. The electric field relaxation layer is disposed on an inside of the RESURF layer so that the electric field relaxation layer is disposed in the cell region. The electric field relaxation layer has a ring shape.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: March 29, 2011
    Assignee: Denso Corporation
    Inventors: Takeo Yamamoto, Eiichi Okuno
  • Patent number: 7906388
    Abstract: A semiconductor device is formed by forming a second trench 120 at the base of a first trench 18, depositing insulator 124 at the base of the second trench 120, and then etching cavities 26 laterally from the sidewalls of the second trench, but not the base which is protected by insulator 124. The invention may in particular be used to form semiconductor devices with cavities under the active components, or by filling the cavities to form silicon on insulator or silicon on conductor devices.
    Type: Grant
    Filed: April 12, 2006
    Date of Patent: March 15, 2011
    Assignee: NXP B.V.
    Inventor: Jan Sonsky
  • Patent number: 7902645
    Abstract: A semiconductor device, a semiconductor element, and a substrate are provided, which allow the semiconductor element to be provided with a reduced size when combined. The semiconductor device has a rectangular semiconductor element mounted on a substrate formed with an external input terminal, an external output terminal, and a plurality of wiring patterns connected to each of the external input terminal and the external output terminal. The semiconductor element includes a grayscale voltage generating unit for generating a plurality of grayscale voltages by dividing a reference voltage, a plurality of electrodes for the reference voltage formed in the neighborhood of the grayscale voltage generating unit; and an internal wiring for connecting the grayscale voltage generating unit and the reference voltage electrodes. The substrate includes a wiring pattern for the reference voltage for connecting the external input terminal and the reference voltage electrodes.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: March 8, 2011
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Akira Nakayama
  • Patent number: 7898027
    Abstract: A MOS device includes a semiconductor substrate having a first conductive type, a source region, a gate structure, and a drain region having a second conductive type. The gate structure is formed on the semiconductor substrate and substantially parallel to a first direction. The source region and the drain region are both disposed in the semiconductor substrate, and on two opposite sides of the gate structure. The source region includes at least a source doped region having the second conductive type, and at least a source contact region having the first conductive type, and the source doped region and the source contact region are alternately arranged along the first direction.
    Type: Grant
    Filed: July 16, 2007
    Date of Patent: March 1, 2011
    Assignee: United Microelectronics Corp.
    Inventor: Chih-Nan Cheng
  • Patent number: 7897459
    Abstract: A through electrode is formed prior to fabricating a semiconductor device by using a standard manufacturing method. Aside face of the through electrode is insulated from a semiconductor substrate by an insulating film, while the top face thereof is covered with a protective insulating film. These insulating films covering the through electrode protect a conductor of the through electrode and prevent emission of a contaminant from the conductor. Standard manufacturing conditions can be applied without change.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: March 1, 2011
    Assignee: Elpida Memory, Inc.
    Inventor: Shiro Uchiyama
  • Patent number: 7893467
    Abstract: A silicon carbide semiconductor device includes a substrate; a drift layer having a first conductivity type; an insulating layer; a Schottky electrode; an ohmic electrode; a resurf layer; and second conductivity type layers. The drift layer and the second conductivity type layers provide multiple PN diodes. Each second conductivity type layer has a radial width with respect to a center of a contact region between the Schottky electrode and the drift layer. A radial width of one of the second conductivity type layers is smaller than that of another one of the second conductivity type layers, which is disposed closer to the center of the contact region than the one of the second conductivity type layers.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: February 22, 2011
    Assignee: DENSO CORPORATION
    Inventors: Takeo Yamamoto, Eiichi Okuno
  • Patent number: 7868397
    Abstract: In a vertical semiconductor device including a first base layer of a first conductivity type, second base layers of a second conductivity type, emitter layer of the first conductive type and gate electrodes which are formed at one main surface of the first base layer and including a buffer layer of the first conductivity type, a collector layer of the second conductivity type and a collector electrode which are formed at the other main surface of the first base layer, an electric field relaxing structure selectively formed outside from the second base layers and the collector layer is formed expect the region below the electric field relaxing structure.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: January 11, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masanori Tsukuda, Ichiro Omura
  • Patent number: 7868378
    Abstract: An LDMOS transistor includes a gate including a conductive material over an insulator material, a source including a first impurity region and a second impurity region, a third impurity region, and a drain including a fourth impurity region and a fifth impurity region. The first impurity region is of a first type, and the second impurity region is of an opposite second type. The third impurity region extends from the source region under the gate and is of the first type. The fourth impurity region is of the second type, the fifth impurity region is of the second type, and the fourth impurity region impinges the third impurity region.
    Type: Grant
    Filed: July 17, 2006
    Date of Patent: January 11, 2011
    Assignee: Volterra Semiconductor Corporation
    Inventors: Marco A. Zuniga, Budong You, Yang Lu
  • Patent number: 7855415
    Abstract: A semiconductor power device includes a drift region of a first conductivity type, a well region extending above the drift region and having a second conductivity type opposite the first conductivity type, an active trench extending through the well region and into the drift region, source regions having the first conductivity type formed in the well region adjacent the active trench, and a first termination trench extending below the well region and disposed at an outer edge of an active region of the device. The sidewalls and bottom of the active trench are lined with dielectric material, and substantially filled with a first conductive layer forming an upper electrode and a second conductive layer forming a lower electrode, the upper electrode being disposed above the lower electrode and separated therefrom by inter-electrode dielectric material.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: December 21, 2010
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Ashok Challa, Jaegil Lee, Jinyoung Jung, Hocheol Jang
  • Patent number: 7851883
    Abstract: This invention aims at providing an inexpensive semiconductor device having a parasitic diode and lowering an hfe of a parasitic PNP transistor and a manufacturing method thereof. Such semiconductor device includes a P-type silicon substrate and a gate electrode formed above the P-type silicon substrate. The P-type silicon substrate includes an N-type well layer, an N-type buried layer, a P-type body layer, an N-type source layer formed in the P-type body layer, and a drain contact layer formed in the N-type well layer. The P-type body layer and the N-type source layer are formed by self alignment that uses the gate electrode as a mask. The N-type drain contact layer is formed opposite the N-type source layer across the P-type body layer formed below the gate electrode. The N-type buried layer is formed below the P-type body layer.
    Type: Grant
    Filed: March 10, 2005
    Date of Patent: December 14, 2010
    Assignee: Panasonic Corporation
    Inventors: Masaki Inoue, Akira Ohdaira
  • Patent number: 7851314
    Abstract: A short channel Lateral MOSFET (LMOS) and method are disclosed with interpenetrating drain-body protrusions (IDBP) for reducing channel-on resistance while maintaining high punch-through voltage. The LMOS includes lower device bulk layer; upper source and upper drain region both located atop lower device bulk layer; both upper source and upper drain region are in contact with an intervening upper body region atop lower device bulk layer; both upper drain and upper body region are shaped to form a drain-body interface; the drain-body interface has an IDBP structure with a surface drain protrusion lying atop a buried body protrusion while revealing a top body surface area of the upper body region; gate oxide-gate electrode bi-layer disposed atop the upper body region forming an LMOS with a short channel length defined by the horizontal length of the top body surface area delineated between the upper source region and the upper drain region.
    Type: Grant
    Filed: April 30, 2008
    Date of Patent: December 14, 2010
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Shekar Mallikarjunaswamy, Amit Paul
  • Patent number: 7851857
    Abstract: A dual current path LDMOSFET transistor (40) is provided which includes a substrate (400), a graded buried layer (401), an epitaxial drift region (404) in which a drain region (416) is formed, a first well region (406) in which a source region (412) is formed, a gate electrode (420) formed adjacent to the source region (412) to define a first channel region (107), and a current routing structure that includes a buried RESURF layer (408) in ohmic contact with a second well region (414) formed in a predetermined upper region of the epitaxial layer (404) so as to be completely covered by the gate electrode (420), the current routing structure being spaced apart from the first well region (406) and from the drain region (416) on at least a side of the drain region to delineate separate current paths from the source region and through the epitaxial layer.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: December 14, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Yue Fu, Ronghua Zhu, Vishnu K. Khemka, Amitava Bose, Todd C. Roggenbauer
  • Patent number: 7838969
    Abstract: A diode is disclosed. One embodiment provides a semiconductor body having a front and a back, opposite the front in a vertical direction of the semiconductor body. The semiconductor body contains, successively in the vertical direction from the back to the front, a heavily n-doped zone, a weakly n-doped zone, a weakly p-doped zone and a heavily p-doped zone. In the vertical direction, the weakly p-doped zone has a thickness of at least 25% and at most 50% of the thickness of the semiconductor body.
    Type: Grant
    Filed: January 3, 2008
    Date of Patent: November 23, 2010
    Assignee: Infineon Technologies AG
    Inventors: Hans-Joachim Schulze, Franz-Josef Niedernostheide, Reiner Barthelmess
  • Patent number: 7829947
    Abstract: Lateral DMOS devices having improved drain contact structures and methods for making the devices are disclosed. A semiconductor device comprises a semiconductor substrate; an epitaxial layer on top of the substrate; a drift region at a top surface of the epitaxial layer; a source region at a top surface of the epitaxial layer; a channel region between the source and drift regions; a gate positioned over a gate dielectric on top of the channel region; and a drain contact trench that electrically connects the drift layer and substrate. The contact trench includes a trench formed vertically from the drift region, through the epitaxial layer to the substrate and filled with an electrically conductive drain plug; electrically insulating spacers along sidewalls of the trench; and an electrically conductive drain strap on top of the drain contact trench that electrically connects the drain contact trench to the drift region.
    Type: Grant
    Filed: March 17, 2009
    Date of Patent: November 9, 2010
    Assignee: Alpha & Omega Semiconductor Incorporated
    Inventor: François Hébert
  • Publication number: 20100276779
    Abstract: A vertical transient voltage suppressing (TVS) device includes a semiconductor substrate of a first conductivity type where the substrate is heavily doped, an epitaxial layer of the first conductivity type formed on the substrate where the epitaxial layer has a first thickness, and a base region of a second conductivity type formed in the epitaxial layer where the base region is positioned in a middle region of the epitaxial layer. The base region and the epitaxial layer provide a substantially symmetrical vertical doping profile on both sides of the base region. In one embodiment, the base region is formed by high energy implantation. In another embodiment, the base region is formed as a buried layer. The doping concentrations of the epitaxial layer and the base region are selected to configure the TVS device as a punchthrough diode based TVS or an avalanche mode TVS.
    Type: Application
    Filed: April 30, 2009
    Publication date: November 4, 2010
    Applicant: Alpha & Omega Semiconductor, Inc.
    Inventors: Lingpeng Guan, Madhur Bobde, Anup Bhalla
  • Patent number: 7821082
    Abstract: A lateral diffused metal oxide semiconductor transistor is disclosed. A p-type bulk is disposed on a substrate. An n-type well region is disposed in the p-type bulk. A plurality of field oxide layers are disposed on the p-type bulk and the n-type well region. A gate structure is disposed on a portion of the p-type bulk and one of the plurality of field oxide layers. At least one deep trench isolation structure is disposed in the p-type bulk and adjacent to the n-type well region.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: October 26, 2010
    Assignee: Vanguard International Semiconductor Corporation
    Inventors: Kwang-Ming Lin, Shih-Chieh Pu, Shih-Chan Chen
  • Patent number: 7816756
    Abstract: A power semiconductor device includes: a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type formed on a first semiconductor layer and alternately arranged along at least one direction parallel to an upper face of the first semiconductor layer; a fourth semiconductor layer of the second conductivity type selectively formed in an upper face of the second and third semiconductor layers; and a control electrode formed above the second, third and fourth semiconductor layers via a gate insulating film. The control electrode includes: first portions periodically arranged along a first direction selected from arranging directions of the third semiconductor layer, the third semiconductor layer has a shortest arrangement period in the first direction, and second portions periodically arranged along a second direction, the second direction being parallel to the upper face of the first semiconductor layer and crossing the first direction.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: October 19, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Wataru Saito
  • Patent number: 7812402
    Abstract: In the upper surface of a p? substrate, an n-type impurity region is formed. In the upper surface of the n-type impurity region, a p-well is formed. Also in the upper surface of the n-type impurity region, a p+-type source region and a p+-type drain region are formed. In the upper surface of the p-well, an n+-type drain region and an n+-type source region are formed. In the p? substrate, an n+ buried layer having an impurity concentration higher than that of the n-type impurity region is formed. The n+ buried layer is formed in contact with the bottom surface of the n-type impurity region at a greater depth than the n-type impurity region.
    Type: Grant
    Filed: August 2, 2005
    Date of Patent: October 12, 2010
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Kazurnari Hatade
  • Publication number: 20100252904
    Abstract: A semiconductor includes an N-type impurity region provided in a substrate. A P-type RESURF layer is provided at a top face of the substrate in the N-type impurity region. A P-well has an impurity concentration higher than that of the P-type RESURF layer, and makes contact with the P-type RESURF layer at the top face of the substrate in the N-type impurity region. A first high-voltage-side plate is electrically connected to the N-type impurity region, and a low-voltage-side plate is electrically connected to a P-type impurity region. A lower field plate is capable of generating a lower capacitive coupling with the substrate. An upper field plate is located at a position farther from the substrate than the lower field plate, and is capable of generating an upper capacitive coupling with the lower field plate whose capacitance is greater than the capacitance of the lower capacitive coupling.
    Type: Application
    Filed: January 11, 2010
    Publication date: October 7, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Tetsuo Takahashi, Takami Otsuki
  • Patent number: 7804150
    Abstract: A field effect transistor includes a trench gate extending into a semiconductor region. The trench gate has a front wall facing a drain region and a side wall perpendicular to the front wall. A channel region extends along the side wall of the trench gate, and a drift region extends at least between the drain region and the trench gate. The drift region includes a stack of alternating conductivity type silicon layers.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: September 28, 2010
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Chang-ki Jeon, Gary Dolny
  • Patent number: 7786532
    Abstract: The relationship between a distance Ls between a base layer and an n type buffer layer formed on the surface of a drift layer and the thickness t of a semiconductor substrate in contact with the drift layer is set to Ls?t?2×Ls. A loss upon turn-off of a high breakdown voltage semiconductor device can be reduced without deteriorating breakdown voltage characteristics.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: August 31, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventor: Tomohide Terashima
  • Patent number: 7777274
    Abstract: A power semiconductor component includes a semiconductor body and a field electrode. The semiconductor body has a drift zone of a first conduction type and a further component defining a junction therebetween. The junction is configured to cause a space charge zone to propagate when a reverse voltage is applied to the junction. The field electrode is arranged adjacent to the drift zone, and is insulated from the semiconductor body by at least a dielectric layer. The dielectric layer has a first section and a second section, the first section arranged nearer to the junction and having a higher dielectric constant than the second section.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: August 17, 2010
    Assignee: Infineon Technologies Austria AG
    Inventors: Anton Mauder, Hans-Joachim Schulze
  • Patent number: 7772668
    Abstract: A field effect transistor (FET) includes a pair of trenches extending into a semiconductor region. Each trench includes a first shield electrode in a lower portion of the trench and a gate electrode in an upper portion of the trench over but insulated from the shield electrode. First and second well regions of a first conductivity type laterally extend in the semiconductor region between the pair of trenches and abut sidewalls of the pair of trenches. The first and second well regions are vertically spaced from one another by a first drift region of a second conductivity type. The gate electrode and the first shield electrode are positioned relative to the first and second well regions such that a channel is formed in each of the first and second well regions when the FET is biased in the on state.
    Type: Grant
    Filed: December 26, 2007
    Date of Patent: August 10, 2010
    Assignee: Fairchild Semiconductor Corporation
    Inventor: James Pan