Patents by Inventor Florin Udrea
Florin Udrea 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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Publication number: 20090058498Abstract: A half bridge circuit has a first switch having at least one control gate and a second switch having at least two control gates. A first driver has an output connected to a control gate of the first switch. A second driver has an output connected to a first control gate of the second switch. The output of the first driver is connected to a second control gate of the second switch by a circuit arrangement such that when the first driver is operated to apply a high, positive voltage to the control gate of the first switch, a positive voltage is applied to the second control gate of the second switch, and such that when the first driver is operated to apply a low, zero or small voltage to the control gate of the first switch, a negative voltage is applied to said second control gate of the second switch.Type: ApplicationFiled: August 29, 2007Publication date: March 5, 2009Applicant: Cambridge Semiconductor LimitedInventors: Florin UDREA, Nishad Udugampola, Gehan Anil Joseph Amaratunga
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Patent number: 7495300Abstract: A gas-sensing semiconductor device is fabricated on a silicon substrate having a thin silicon oxide insulating layer in which a resistive heater made of a CMOS compatible high temperature metal is embedded. The high temperature metal is tungsten. The device includes at least one sensing area provided with a gas-sensitive layer separated from the heater by an insulating layer. As one of the final fabrication steps, the substrate is back-etched so as to form a thin membrane in the sensing area. Except for the back-etch and the gas-sensitive layer formation, that are carried out post-CMOS, all other layers, including the tungsten resistive heater, are made using a CMOS process employing tungsten metallisation. The device can be monolithically integrated with the drive, control and transducing circuitry using low cost CMOS processing. The heater, the insulating layer and other layers are made within the CMOS sequence and they do not require extra masks or processing.Type: GrantFiled: March 30, 2005Date of Patent: February 24, 2009Assignee: University of WarwickInventors: Julian William Gardner, James Anthony Covington, Florin Udrea
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Patent number: 7485509Abstract: A semiconductor device includes a first field effect transistor including a source and a gate and disposed in a silicon carbide substrate; and a second field effect transistor including a drain and a gate and disposed in the substrate. The drain of the second field effect transistor connects to the source of the first field effect transistor. The gate of the second field effect transistor connects to the gate of the first field effect transistor.Type: GrantFiled: November 9, 2006Date of Patent: February 3, 2009Assignee: DENSO CORPORATIONInventors: Rajesh Kumar, Florin Udrea, Andrei Mihaila
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Publication number: 20090008674Abstract: Double gate IGBT having both gates referred to a cathode in which a second gate is for controlling flow of hole current. In on-state, hole current can be largely suppressed. While during switching, hole current is allowed to flow through a second channel. Incorporating a depletion-mode p-channel MOSFET having a pre-formed hole channel that is turned ON when 0V or positive voltages below a specified threshold voltage are applied between second gate and cathode, negative voltages to the gate of p-channel are not used. Providing active control of holes amount that is collected in on-state by lowering base transport factor through increasing doping and width of n well or by reducing injection efficiency through decreasing doping of deep p well. Device includes at least anode, cathode, semiconductor substrate, n? drift region, first & second gates, n+ cathode region; p+ cathode short, deep p well, n well, and pre-formed hole channel.Type: ApplicationFiled: September 27, 2007Publication date: January 8, 2009Inventor: Florin Udrea
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Patent number: 7465964Abstract: A high voltage/power semiconductor device has a substrate, an insulating layer on the substrate, and a semiconductor layer on the insulating layer. Low and high voltage terminals are connected to the semiconductor layer. The device has a control terminal. The semiconductor layer includes a drift region and a relatively highly doped injector region between the drift region and the high voltage terminal. The device has a relatively highly doped region in electrical contact with the highly doped injector region and the high voltage terminal and forming a semiconductor junction with the substrate. The combination of the insulating layer and the relatively highly doped region of the first conductivity type effectively isolate the highly doped injector region from the substrate.Type: GrantFiled: December 30, 2005Date of Patent: December 16, 2008Assignee: Cambridge Semiconductor LimitedInventor: Florin Udrea
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Patent number: 7411272Abstract: A power semiconductor device has an active region that includes a drift region. At least a portion of the drift region is provided in a membrane which has opposed top and bottom surfaces. In one embodiment, the top surface of the membrane has electrical terminals connected directly or indirectly thereto to allow a voltage to be applied laterally across the drift region. In another embodiment, at least one electrical terminal is connected directly or indirectly to the top surface and at least one electrical terminal is connected directly or indirectly to the bottom surface to allow a voltage to be applied vertically across the drift region. In each of these embodiments, the bottom surface of the membrane does not have a semiconductor substrate positioned adjacent thereto.Type: GrantFiled: July 6, 2005Date of Patent: August 12, 2008Assignee: Cambridge Semiconductor LimitedInventors: Florin Udrea, Gehan A. J. Amaratunga
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Patent number: 7381606Abstract: A bipolar high voltage/power semiconductor device has a low voltage terminal and a high voltage terminal. The device has a drift region of a first conductivity type and having first and second ends. In one example, a region of the second conductivity type is provided at the second end of the drift region connected directly to the high voltage terminal. In another example, a buffer region of the first conductivity type is provided at the second end of the drift region and a region of a second conductivity type is provided on the other side of the buffer region and connected to the high voltage terminal. Plural electrically floating island regions are provided within the drift region at or towards the second end of the drift region, the plural electrically floating island regions being of the first conductivity type and being more highly doped than the drift region.Type: GrantFiled: October 17, 2007Date of Patent: June 3, 2008Assignee: Cambridge Semiconductor LimitedInventor: Florin Udrea
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Patent number: 7355226Abstract: This invention is generally concerned with power semiconductors such as power MOS transistors, insulated gate by bipolar transistors (IGBTs), high voltage diodes and the like, and method for their fabrication. A power semiconductor, the semiconductor comprising a power device, said power device having first and second electrical contact regions and a drift region extending therebetween; and a semiconductor substrate mounting said device; and wherein said power semiconductor includes an electrically insulating layer between said semiconductor substrate and said power device, said electrically insulating layer having a thickness of at least 5 ?m.Type: GrantFiled: May 1, 2006Date of Patent: April 8, 2008Assignee: Cambridge Semiconductor LimitedInventors: Gehan Anil Joseph Amaratunga, Florin Udrea
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Publication number: 20080070350Abstract: A bipolar high voltage/power semiconductor device has a low voltage terminal and a high voltage terminal. The device has a drift region of a first conductivity type and having first and second ends. In one. example, a region of the second conductivity type is provided at the second end of the drift region connected directly to the high voltage terminal. In another example, a buffer region of the first conductivity type is provided at the second end of the drift region and a region of a second conductivity type is provided on the other side of the buffer region and connected to the high voltage terminal. Plural electrically floating island regions are provided within the drift region at or towards the second end of the drift region, the plural electrically floating island regions being of the first conductivity type and being more highly doped than the drift region.Type: ApplicationFiled: October 17, 2007Publication date: March 20, 2008Applicant: Cambridge Semiconductor LimitedInventor: Florin UDREA
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Publication number: 20080054439Abstract: A power electronic package includes: first and second high thermal conductivity insulating non-planar substrates; and multiple semiconductor chips and electronic components between the substrates. Each substrate includes multiple electrical insulator layers and patterned electrical conductor layers connecting to the electronic components, and further includes multiple raised regions or posts, which are bonded together so that the substrates are mechanically and electrically connected. The number, arrangement, and shape of the raised regions or posts are adjusted to have mechanical separation between the substrates. The electrical conductor layers are separated and isolated one another so that multiple electric circuits are provided on at least one of the substrates.Type: ApplicationFiled: August 29, 2006Publication date: March 6, 2008Applicants: DENSO CORPORATION, University of Cambridge, The University of SheffieldInventors: Rajesh Kumar Malhan, C. Mark Johnson, Cyril Buttay, Jeremy Rashid, Florin Udrea
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Publication number: 20080012043Abstract: A bipolar high voltage/power semiconductor device has a drift region having adjacent its ends regions of different conductivity types respectively. High and low voltage terminals are provided. A first insulated gate terminal and a second insulated gate terminal are also provided. One or more drive circuits provide appropriate voltages to the first and second insulated gate terminals so as to allow current conduction in a first direction or in a second direction that is opposite the first direction.Type: ApplicationFiled: July 14, 2006Publication date: January 17, 2008Applicant: Cambridge Semiconductor LimitedInventors: Florin Udrea, Nishad Udugampola, Gehan A.J. Amaratunga
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Patent number: 7301220Abstract: A bipolar high voltage/power semiconductor device has a low voltage terminal and a high voltage terminal. The device has a drift region of a first conductivity type and having first and second ends. In one example, a region of the second conductivity type is provided at the second end of the drift region connected directly to the high voltage terminal. In another example, a buffer region of the first conductivity type is provided at the second end of the drift region and a region of a second conductivity type is provided on the other side of the buffer region and connected to the high voltage terminal. Plural electrically floating island regions are provided within the drift region at or towards the second end of the drift region, the plural electrically floating island regions being of the first conductivity type and being more highly doped than the drift region.Type: GrantFiled: May 20, 2005Date of Patent: November 27, 2007Assignee: Cambridge Semiconductor LimitedInventor: Florin Udrea
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Publication number: 20070200117Abstract: A silicon carbide semiconductor device includes a substrate and a junction field effect transistor. The transistor includes: a first semiconductor layer disposed on the substrate; a first gate layer disposed on a surface of the first semiconductor layer; a first channel layer adjacent to the first gate layer on the substrate; a first source layer connecting to the first channel layer electrically; a second gate layer adjacent to the first channel layer to sandwich the first channel layer; a second channel layer adjacent to the second gate layer to sandwich the second gate layer; a third gate layer adjacent to the second channel layer to sandwich the second channel layer; and a second source layer connecting to the second channel layer electrically.Type: ApplicationFiled: April 17, 2007Publication date: August 30, 2007Applicant: DENSO CORPORATIONInventors: Rajesh Kumar, Andrei Mihaila, Florin Udrea
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Publication number: 20070158678Abstract: A high voltage/power semiconductor device has a relatively lowly doped substrate, an insulating layer on the substrate, and a semiconductor layer on the insulating layer. A low voltage terminal and a high voltage terminal are each electrically connected to the semiconductor layer. The device has a control terminal. The semiconductor layer includes a drift region of a first conductivity type, the substrate being of the second conductivity type. The semiconductor layer includes a relatively highly doped injector region of the second conductivity type between the drift region and the high voltage terminal, said relatively highly doped injector region being in electrical contact with the high voltage terminal and not being connected via any semiconductor layer to the substrate. The device has a relatively highly doped region of the first conductivity type in electrical contact with the said highly doped injector region and the high voltage terminal and forming a semiconductor junction with the substrate.Type: ApplicationFiled: December 30, 2005Publication date: July 12, 2007Applicant: CAMBRIDGE SEMICONDUCTOR LIMITEDInventor: Florin Udrea
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Patent number: 7235439Abstract: A power semiconductor device has an active region that includes a drift region. At least a portion of the drift region is provided in a membrane which has opposed top and bottom surfaces. In one embodiment, the top surface of the membrane has electrical terminals connected directly or indirectly thereto to allow a voltage to be applied laterally across the drift region. In another embodiment, at least one electrical terminal is connected directly or indirectly to the top surface and at least one electrical terminal is connected directly or indirectly to the bottom surface to allow a voltage to be applied vertically across the drift region. In each of these embodiments, the bottom surface of the membrane does not have a semiconductor substrate positioned adjacent thereto.Type: GrantFiled: July 6, 2005Date of Patent: June 26, 2007Assignee: Cambridge Semiconductor LimitedInventors: Florin Udrea, Gehan A J Amaratunga
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Patent number: 7230275Abstract: A silicon carbide semiconductor device includes a substrate and a junction field effect transistor. The transistor includes: a first semiconductor layer disposed on the substrate; a first gate layer disposed on a surface of the first semiconductor layer; a first channel layer adjacent to the first gate layer on the substrate; a first source layer connecting to the first channel layer electrically; a second gate layer adjacent to the first channel layer to sandwich the first channel layer; a second channel layer adjacent to the second gate layer to sandwich the second gate layer; a third gate layer adjacent to the second channel layer to sandwich the second channel layer; and a second source layer connecting to the second channel layer electrically.Type: GrantFiled: November 10, 2004Date of Patent: June 12, 2007Assignee: Denso CorporationInventors: Rajesh Kumar, Andrei Mihaila, Florin Udrea
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Patent number: 7230314Abstract: A semiconductor device having an active region is formed in a layer provided on a semiconductor substrate. At least a portion of the semiconductor substrate below at least a portion of the active region is removed such that the portion of the active region is provided in a membrane defined by that portion of the layer below which the semiconductor substrate has been removed. A heat conducting and electrically insulating layer is applied to the bottom surface of the membrane. The heat conducting and electrically insulating layer has a thermal conductivity that is higher than the thermal conductivity of the membrane so that the heat conducting and electrically insulating layer allows heat to pass from the active region into the heat conducting and electrically insulating layer during normal operation of the device.Type: GrantFiled: March 28, 2003Date of Patent: June 12, 2007Assignee: Cambridge Semiconductor LimitedInventors: Florin Udrea, Gehan A. J. Amaratunga
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Publication number: 20070120187Abstract: This invention is generally concerned with semiconductor-on-insulator devices, particularly for high voltage applications. A lateral semiconductor-on-insulator device is described, comprising: a semiconductor substrate; an insulating layer on said semiconductor substrate; and a lateral semiconductor device on said insulator; said lateral semiconductor device having: a first region of a first conductivity type; a second region of a second conductivity type laterally spaced apart from said first region; and a drift region extending in a lateral direction between said first region and said second region; and wherein said drift region comprises at least one first zone and at least one second zone adjacent a said first zone, a said first zone having said second conductivity type, a said second zone being an insulating zone, a said first zone being tapered to narrow towards said first region.Type: ApplicationFiled: May 13, 2003Publication date: May 31, 2007Applicant: CAMBRIDGE SEMICONDUCTOR LIMITEDInventors: Florin Udrea, David Garner
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Publication number: 20070102708Abstract: A semiconductor device includes a first field effect transistor including a source and a gate and disposed in a silicon carbide substrate; and a second field effect transistor including a drain and a gate and disposed in the substrate. The drain of the second field effect transistor connects to the source of the first field effect transistor. The gate of the second field effect transistor connects to the gate of the first field effect transistor.Type: ApplicationFiled: November 9, 2006Publication date: May 10, 2007Applicant: DENSO CORPORATIONInventors: Rajesh Kumar, Florin Udrea, Andrei Mihaila
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Patent number: 7164154Abstract: A silicon carbide semiconductor device includes: a semiconductor substrate including first and second gate layers, a channel layer, a source layer, and a trench; a gate wiring having a first portion and a plurality of second portions; and a source wiring having a third portion and a plurality of fourth portions. The trench extends in a predetermined extending direction. The first portion connects to the first gate layer in the trench, and extends to the extending direction. The second portions protrude perpendicularly to be a comb shape. The third portion extends to the extending direction. The fourth portions protrude perpendicularly to be a comb shape, and electrically connect to the source layer. Each of the second portions connects to the second gate layer through a contact hole.Type: GrantFiled: November 24, 2004Date of Patent: January 16, 2007Assignee: Denso CorporationInventors: Rajesh Kumar, Yuichi Takeuchi, Mitsuhiro Kataoka, Suhail Rashid Jeremy, Andrei Mihaila, Florin Udrea