Of Field-effect Transistors With Schottky Gate (epo) Patents (Class 257/E29.041)
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Patent number: 8610213Abstract: A semiconductor device capable of ensuring a withstand voltage of a transistor and reducing a forward voltage of a Schottky barrier diode in a package with the transistor and the Schottky barrier diode formed on chip, and a semiconductor package formed by a resin package covering the semiconductor device are provided. The semiconductor device 1 includes a semiconductor layer 22, a transistor area D formed on the semiconductor layer 22 and constituting the transistor 11, and a diode area C formed on the semiconductor layer 22 and constituting the Schottky barrier diode 10. The semiconductor layer 22 in the diode area C is thinner than the semiconductor layer 22 in the transistor area D.Type: GrantFiled: December 9, 2011Date of Patent: December 17, 2013Assignee: Rohm Co., Ltd.Inventor: Yoshimochi Kenichi
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Patent number: 8592878Abstract: Embodiments include semiconductor devices with low leakage Schottky contacts. An embodiment is formed by providing a partially completed semiconductor device including a substrate, a semiconductor on the substrate, and a passivation layer on the semiconductor, and using a first mask, locally etching the passivation layer to expose a portion of the semiconductor. Without removing the first mask, a Schottky contact is formed of a first material on the exposed portion of the semiconductor, and the first mask is removed. Using a further mask, a step-gate conductor of a second material electrically coupled to the Schottky contact is formed overlying parts of the passivation layer adjacent to the Schottky contact. By minimizing the process steps between opening the Schottky contact window in the passivation layer and forming the Schottky contact material in this window, the gate leakage of a resulting field effect device having a Schottky gate may be substantially reduced.Type: GrantFiled: March 8, 2011Date of Patent: November 26, 2013Assignee: Freescale Semiconductor, Inc.Inventors: Bruce M. Green, Haldane S. Henry, Chun-Li Liu, Karen E. Moore, Matthias Passlack
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Patent number: 8569843Abstract: A bidirectional switch includes a plurality of unit cells 11 including a first ohmic electrode 15, a first gate electrode 17, a second gate electrode 18, and a second ohmic electrode 16. The first gate electrodes 15 are electrically connected via a first interconnection 31 to a first gate electrode pad 43. The second gate electrodes 18 are electrically connected via a second interconnection 32 to a second gate electrode pad 44. A unit cell 11 including a first gate electrode 17 having the shortest interconnect distance from the first gate electrode pad 43 includes a second gate electrode 18 having the shortest interconnect distance from the second gate electrode pad 44.Type: GrantFiled: November 29, 2012Date of Patent: October 29, 2013Assignee: Panasonic CorporationInventors: Manabu Yanagihara, Kazushi Nakazawa, Tatsuo Morita, Yasuhiro Uemoto
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Patent number: 8344463Abstract: A bidirectional switch includes a plurality of unit cells 11 including a first ohmic electrode 15, a first gate electrode 17, a second gate electrode 18, and a second ohmic electrode 16. The first gate electrodes 15 are electrically connected via a first interconnection 31 to a first gate electrode pad 43. The second gate electrodes 18 are electrically connected via a second interconnection 32 to a second gate electrode pad 44. A unit cell 11 including a first gate electrode 17 having the shortest interconnect distance from the first gate electrode pad 43 includes a second gate electrode 18 having the shortest interconnect distance from the second gate electrode pad 44.Type: GrantFiled: July 10, 2009Date of Patent: January 1, 2013Assignee: Panasonic CorporationInventors: Manabu Yanagihara, Kazushi Nakazawa, Tatsuo Morita, Yasuhiro Uemoto
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Patent number: 8227867Abstract: A portion of a top semiconductor layer of a semiconductor-on-insulator (SOI) substrate is patterned into a semiconductor fin having substantially vertical sidewalls. A portion of a body region of the semiconductor fin is exposed on a top surface of the semiconductor fin between two source regions having a doping of a conductivity type opposite to the body region of the semiconductor fin. A metal semiconductor alloy portion is formed directly on the two source regions and the top surface of the exposed body region between the two source regions. The doping concentration of the exposed top portion of the body region may be increased by ion implantation to provide a low-resistance contact to the body region, or a recombination region having a high-density of crystalline defects may be formed. A hybrid surface semiconductor-on-insulator (HSSOI) metal-oxide-semiconductor-field-effect-transistor (MOSFET) thus formed has a body region that is electrically tied to the source region.Type: GrantFiled: December 23, 2008Date of Patent: July 24, 2012Assignee: International Business Machines CorporationInventors: Brent A. Anderson, Edward J. Nowak
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Patent number: 8174048Abstract: A III-nitride device includes a recessed electrode to produce a nominally off, or an enhancement mode, device. By providing a recessed electrode, a conduction channel formed at the interface of two III-nitride materials is interrupted when the electrode contact is inactive to prevent current flow in the device. The electrode can be a schottky contact or an insulated metal contact. Two ohmic contacts can be provided to form a rectifier device with nominally off characteristics. The recesses formed with the electrode can have sloped sides. The electrode can be formed in a number of geometries in conjunction with current carrying electrodes of the device. A nominally on device, or pinch resistor, is formed when the electrode is not recessed. A diode is also formed by providing non-recessed ohmic and schottky contacts through an insulator to an AlGaN layer.Type: GrantFiled: January 21, 2005Date of Patent: May 8, 2012Assignee: International Rectifier CorporationInventor: Robert Beach
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Patent number: 7939865Abstract: In one embodiment, a metal-semiconductor field effect transistor (MESFET) comprises a first silicon layer, an insulator layer formed on the first silicon layer, and a second silicon layer formed on the insulator layer. A gate region, a source region, and a drain region are formed in the second silicon layer. A first partial trench is formed in the second silicon layer between at least a portion of the gate region and at least a portion of the source region, wherein the first partial trench stops short of the insulator layer. A second partial trench formed in the second silicon layer between at least a portion of the gate region and at least a portion of the drain region, wherein the second partial trench stops short of the insulator layer. First and second oxide spacers are formed in the first and second partial trenches. The first and second oxide spacers and the source region, gate region, and the drain region are substantially planar.Type: GrantFiled: January 22, 2009Date of Patent: May 10, 2011Assignee: Honeywell International Inc.Inventor: Paul Fechner
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Patent number: 7935620Abstract: Methods and apparatus are described for semiconductor devices. A method comprises providing a partially completed semiconductor device including a substrate, a semiconductor on the substrate, and a passivation layer on the semiconductor, and using a first mask, locally etching the passivation layer to expose a portion of the semiconductor, and without removing the first mask, forming a Schottky contact of a first material on the exposed portion of the semiconductor, then removing the first mask, and using a further mask, forming a step-gate conductor of a second material electrically coupled to the Schottky contact and overlying parts of the passivation layer adjacent to the Schottky contact. By minimizing the process steps between opening the Schottky contact window in the passivation layer and forming the Schottky contact material in this window, the gate leakage of a resulting field effect device having a Schottky gate may be substantially reduced.Type: GrantFiled: December 5, 2007Date of Patent: May 3, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Bruce M. Green, Haldane S. Henry, Chun-Li Liu, Karen E. Moore, Matthias Passlack
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Patent number: 7928480Abstract: A semiconductor device has a semiconductor layer, and a first electrode (Schottky electrode or MIS electrode) and a second electrode (ohmic electrode) which are formed on the semiconductor layer apart from each other. The first electrode has a cross section in the shape of a polygon. A second electrode-side corner of the polygon has an interior angle of which an outward extension line of a bisector crosses the semiconductor layer or the second electrode. The interior angle of such a second electrode-side corner is larger than 90°.Type: GrantFiled: November 30, 2006Date of Patent: April 19, 2011Assignee: Sharp Kabushiki KaishaInventors: Masaharu Yamashita, John Kevin Twynam
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Patent number: 7759760Abstract: A semiconductor switching element, wherein on a semiconductor layer formed on a substrate, or on a semiconductor substrate, a source electrode and a drain electrode are disposed at a predetermined interval in a direction along a surface of the substrate; and a second gate electrode is provided between the source electrode and the drain electrode, the second gate electrode is electrically connected with the source electrode and structured with two types of electrode material layers having Schottky barriers of different heights from each other.Type: GrantFiled: June 29, 2007Date of Patent: July 20, 2010Assignee: Sharp Kabushiki KaishaInventors: Norimasa Yafune, John Kevin Twynam
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Patent number: 7709864Abstract: A rectifier device (10) comprising a multi-layer epitaxial film (12) and a rectifier and a transistor manufactured in the film (12), wherein the transistor is oriented vertically relative to the plane of the rectifier. The rectifier and transistor are separated by a transition zone of inverted bias. The rectifier is a Schottky barrier rectifier, and the transistor is a JFET. More specifically, the device (1) comprises the film (12), a trench (16), a first region (18) associated with an upper portion of the trench (16), and second region (20) associated with a lower portion. The interface between the p+ material of the second region (20) and the n material of the film (12) creates a p+/n junction. The device (10) has use in high frequency, low-loss power circuit applications in which high switching speed and low forward voltage drop are desirable.Type: GrantFiled: April 7, 2006Date of Patent: May 4, 2010Assignee: Diodes Fabtech IncInventors: Roman Hamerski, Chris Hruska, Fazia Hossain
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Patent number: 7705377Abstract: A field effect transistor having a double recess structure, which minimizes an influence exerted on a channel region depending upon the surface state of an outer recess section. In the field effect transistor having such a double recess structure, an ohmic contact layer at the surface of the outer recess section is made to have a thickness so as to be in a to completely depleted state.Type: GrantFiled: September 28, 2006Date of Patent: April 27, 2010Assignee: Oki Semiconductor Co., Ltd.Inventor: Tomoyuki Ohshima
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Patent number: 7700423Abstract: A method of fabricating an epitaxial compound semiconductor III-V wafer suitable for the subsequent fabrication of at least two different types of integrated active devices (such as an HBT and a FET) on such wafer by providing a substrate; growing a first epitaxial structure on the substrate; and growing a second epitaxial structure on the first epitaxial structure.Type: GrantFiled: July 28, 2006Date of Patent: April 20, 2010Assignee: IQE RF, LLCInventors: Paul Cooke, Richard W. Hoffman, Jr., Victor Labyuk, Sherry Qianwen Ye
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Patent number: 7696531Abstract: A semiconductor device includes: an channel layer formed on a semiconductor substrate; a drain electrode and a source electrode both formed on the channel layer apart from each other; a surface passivation film formed on the channel layer so as to cover the channel layer except for the drain electrode and the source electrode; a gate electrode disposed between the drain electrode and the source electrode so as to penetrate the surface passivation film; a field plate electrode provided on the surface passivation film between the drain electrode and the gate electrode at a predetermined distance from the gate electrode; and a connecting plate having a bridge structure connecting the gate electrode to the field plate electrode. The bridge structure may be formed with at least one opening penetrating the connecting plate so as to face the surface passivation film with a predetermined space.Type: GrantFiled: January 25, 2006Date of Patent: April 13, 2010Assignee: Kabushiki Kaisha ToshibaInventor: Akio Miyao
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Patent number: 7692222Abstract: A semiconductor structure and method wherein a recess is disposed in a surface portion of a semiconductor structure and a dielectric film is disposed on and in contract with the semiconductor. The dielectric film has an aperture therein. Portions of the dielectric film are disposed adjacent to the aperture and overhang underlying portions of the recess. An electric contact has first portions thereof disposed on said adjacent portions of the dielectric film, second portions disposed on said underlying portions of the recess, with portions of the dielectric film being disposed between said first portion of the electric contact and the second portions of the electric contact, and third portions of the electric contact being disposed on and in contact with a bottom portion of the recess in the semiconductor structure. The electric contact is formed by atomic layer deposition of an electrically conductive material over the dielectric film and through the aperture in such dielectric film.Type: GrantFiled: November 7, 2006Date of Patent: April 6, 2010Assignee: Raytheon CompanyInventors: Kamal Tabatabaie, Robert B. Hallock
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Patent number: 7655546Abstract: A depletion mode (D-mode) field effect transistor (FET) is monolithically integrated with an enhancement mode (E-mode) FET in a multi-layer structure. The multi-layer structure includes a channel layer overlaid by a barrier layer overlaid by an ohmic contact layer. Source and drain contacts of the D-mode and E-mode FETs are coupled to the ohmic contact layer. A gate contact of the D-mode and E-mode FETs is coupled to the barrier layer. An amorphized region is provided beneath the E-mode gate contact within the barrier layer. The amorphized region forms a buried E-mode Schottky contact with the barrier layer. An alternative embodiment couples the gate contact of the D-mode transistor to a first layer that overlies the barrier layer, and provides a similar D-mode amorphized region within the first layer.Type: GrantFiled: October 11, 2005Date of Patent: February 2, 2010Assignee: TriQuint Semiconductor, Inc.Inventor: Walter Anthony Wohlmuth
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Patent number: 7651905Abstract: An apparatus and method for the reduction of gate leakage in deep sub-micron metal oxide semiconductor (MOS) transistors, especially useful for those used in a cross coupled static random access memory (SRAM) cell, is disclosed. In accordance with the invention, the active element of the SRAM cell is used to reduce the voltage on the gate of its transistor without impacting the switching speed of the circuit. Because the load on the output of the inverter is fixed, a reduction in the gate current is optimized to minimize the impact on the switching waveform of the memory cell. An active element formed by two materials with different Fermi potentials is used as a rectifying junction or diode. The rectifying junction also has a large parallel leakage path, which allows a finite current flow when a signal of opposite polarity is applied across this device.Type: GrantFiled: April 19, 2005Date of Patent: January 26, 2010Assignee: Semi Solutions, LLCInventor: Ashok Kumar Kapoor
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Patent number: 7633135Abstract: This invention discloses a bottom-anode Schottky (BAS) diode that includes an anode electrode disposed on a bottom surface of a semiconductor substrate. The bottom-anode Schottky diode further includes a sinker dopant region disposed at a depth in the semiconductor substrate extending substantially to the anode electrode disposed on the bottom surface of the semiconductor and the sinker dopant region covered by a buried Schottky barrier metal functioning as an Schottky anode.Type: GrantFiled: July 22, 2007Date of Patent: December 15, 2009Assignee: Alpha & Omega Semiconductor, Ltd.Inventor: François Hébert
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Publication number: 20090146191Abstract: Method and apparatus are described for semiconductor devices. The method (100) comprises, providing a partially completed semiconductor device (31-1) including a substrate (21), a semiconductor (22) on the substrate (21) and a passivation layer (25) on the semiconductor (22), and using a first mask (32), locally etching the passivation layer (25) to expose a portion (36) of the semiconductor (22), and without removing the first mask (32) forming a Schottky contact (42-1) of a first material on the exposed portion (36) of the semiconductor (22), then removing the first mask (32) and using a further mask (44), forming a step-gate conductor (48-1) of a second material electrically coupled to the Schottky contact (42-1) and overlying parts (25-1) of the passivation layer (25) adjacent to the Schottky contact (42-1).Type: ApplicationFiled: December 5, 2007Publication date: June 11, 2009Applicant: FREESCALE SEMICONDUCTOR, INC.Inventors: Bruce M. Green, Haldane S. Henry, Chun-Li Liu, Karen E. Moore, Matthias Passlack
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Patent number: 7538362Abstract: The invention relates to a lateral semiconductor diode, in which contact metal fillings (6, 7), which run in trenches (3, 4) in particular in a silicon carbide body (1, 2), are interdigitated at a distance from one another, and a rectifying Schottky or pn junction (18) is provided.Type: GrantFiled: August 29, 2005Date of Patent: May 26, 2009Assignee: Infineon Technologies AGInventors: Gabriel Konrad Dehlinger, Michael Treu
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Patent number: 7504328Abstract: A method of fabricating an N-type Schottky barrier Source/Drain Transistor (N-SSDT) with ytterbium silicide (YbSi2-x) for source and drain is presented. The fabrication of YbSi2-x is compatible with the normal CMOS process but ultra-high vacuum, which is required for ErSi2-x fabrication, is not needed here. To prevent oxidation of ytterbium during ex situ annealing and to improve the film quality, a suitable capping layer stack has been developed.Type: GrantFiled: May 10, 2005Date of Patent: March 17, 2009Assignee: National University of SingaporeInventors: Shiyang Zhu, Jingde Chen, Sungjoo Lee, Ming Fu Li, Jagar Singh, Chunxiang Zhu, Dim-Lee Kwong
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Publication number: 20070202644Abstract: This process for manufacturing a Schottky-barrier MOS transistor on a fully depleted semiconductor film may include depositing a first layer of a first sacrificial material on an active zone of the substrate, forming a silicon layer on top of the first layer of sacrificial material, forming a gate region on top of the silicon layer with interposition of a gate oxide layer, and selective etching of the sacrificial material so as to form a tunnel beneath the gate region. The tunnel is filled with a dielectric second sacrificial material. A controlled lateral etching of the second sacrificial material is performed so as to keep behind a zone of dielectric material beneath the gate region. Silicidation is performed at the location of the source region and drain region and at the location of the etched zone.Type: ApplicationFiled: February 7, 2007Publication date: August 30, 2007Applicant: STMicroelectronics (Crolles 2) SASInventors: Thomas Skotnicki, Stephane Monfray
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Patent number: 6967360Abstract: A semiconductor device and its manufacturing method. The semiconductor device has a semi-insulating GaAs substrate 310, a GaAs buffer layer 321 that is formed on the semi-insulating GaAs substrate 310, AlGaAs buffer layer 322, a channel layer 323, a spacer layer 324, a carrier supply layer 325, a spacer layer 326, a Schottky layer 327 composed of an undoped In0.48Ga0.52P material, and an n+-type GaAs cap layer 328. A gate electrode 330 is formed on the Schottky layer 327, and is composed of LaB6 and has a Schottky contact with the Schottky layer 327, and ohmic electrodes 340 are formed on the n+-type GaAs cap layer 328.Type: GrantFiled: July 14, 2003Date of Patent: November 22, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoshiharu Anda, Akiyoshi Tamura
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Patent number: 6943386Abstract: New pseudomorphic high electron mobility transistors (pHEMT's) with extremely high device linearity having an n+/p+/n camel-gate heterostructure and ?-doped sheet structure is disclosed. For the example of InGaP/InGaAs/GaAs ?-doped pHEMT's with an n+-GaAs/p+-InGaP/n-InGaP camel-gate structure, due to the p-n depletion from p+-InGaP gate to channel region and the presence of large conduction band discontinuity (?Ec) at InGaP/InGaAs heterostructure, the turn-on voltage of gate is larger than 1.7 V. Attributed to the applied gate voltage partly lying on the camel gate and influence of the carrier modulation, the change of total depletion thickness under gate bias is relatively small, and high drain current and linear transconductance can be achieved, simultaneously. The excellent device performances provide a promise for linear and large signal amplifiers and high-frequency circuit applications.Type: GrantFiled: September 23, 2003Date of Patent: September 13, 2005Assignee: National Kaohsiung Normal UniversityInventor: Jung-Hui Tsai