Patent application number | Description | Published |
20100207166 | Gallium Nitride Heterojunction Schottky Diode - A gallium nitride based semiconductor diode includes a substrate, a GaN layer formed on the substrate, an AlGaN layer formed on the GaN layer where the GaN layer and the AlGaN layer forms a cathode region of the diode, a metal layer formed on the AlGaN layer forming a Schottky junction therewith where the metal layer forms an anode electrode of the diode, and a high barrier region formed in the top surface of the AlGaN layer and positioned under an edge of the metal layer. The high barrier region has a higher bandgap energy than the AlGaN layer or being more resistive than the AlGaN layer. | 08-19-2010 |
20100207232 | Gallium Nitride Semiconductor Device With Improved Forward Conduction - A gallium nitride based semiconductor diode includes a substrate, a semiconductor body including a first heavily doped GaN layer and a second lightly doped GaN layer. The semiconductor body includes mesas projecting upwardly from a lower surface where each of the mesas includes the second GaN layer and a portion of the first GaN layer. Schottky contacts are formed on the upper surface of the mesas and ohmic contacts are formed on the lower surface of the semiconductor body. An insulating layer is formed over the Schottky and ohmic contacts and vias are formed in the insulating layer to the Schottky and Ohmic contacts. A first metal pad is formed in a third metal layer and over vias to the Schottky contacts to form an anode electrode. A second metal pad is formed in the third metal layer and over vias to the ohmic contacts to form a cathode electrode. | 08-19-2010 |
20110049564 | Integrated schottky diode in high voltage semiconductor device - This invention discloses a method for manufacturing a semiconductor power device in a semiconductor substrate comprises an active cell area and a termination area. The method comprises the steps of a) growing and patterning a field oxide layer in the termination area and also in the active cell area on a top surface of the semiconductor substrate b) depositing and patterning a polysilicon layer on the top surface of the semiconductor substrate at a gap distance away from the field oxide layer; c) performing a blank body dopant implant to form body dopant regions in the semiconductor substrate substantially aligned with the gap area followed by diffusing the body dopant regions into body regions in the semiconductor substrate; d) implanting high concentration body-dopant regions encompassed in and having a higher dopant concentration than the body regions and e) applying a source mask to implant source regions having a conductivity opposite to the body region with the source regions encompassed in the body regions and surrounded by the high concentration body-dopant regions. | 03-03-2011 |
20110101369 | Gallium nitride semiconductor device with improved termination scheme - This invention discloses a gallium nitride based semiconductor power device disposed in a semiconductor substrate. The power device comprises a termination area disposed at a peripheral area of the semiconductor power device comprises a termination structure having at least a guard ring disposed in a trench filled with doped gallium-based epitaxial layer therein. | 05-05-2011 |
20110103148 | Normally off gallium nitride field effect transistors (FET) - A heterostructure field effect transistor (HFET) gallium nitride (GaN) semiconductor power device comprises a hetero-junction structure comprises a first semiconductor layer interfacing a second semiconductor layer of two different band gaps thus generating an interface layer as a two-dimensional electron gas (2DEG) layer. The power device further comprises a source electrode and a drain electrode disposed on two opposite sides of a gate electrode disposed on top of the hetero-junction structure for controlling a current flow between the source and drain electrodes in the 2DEG layer. The power device further includes a floating gate located between the gate electrode and hetero-junction structure, wherein the gate electrode is insulated from the floating gate with an insulation layer and wherein the floating gate is disposed above and padded with a thin insulation layer from the hetero-junction structure and wherein the floating gate is charged for continuously applying a voltage to the 2DEG layer to pinch off the current flowing in the 2DEG layer between the source and drain electrodes whereby the HFET semiconductor power device is a normally off device. | 05-05-2011 |
20110204442 | CORNER LAYOUT FOR SUPERJUNCTION DEVICE - A superjunction device and methods for layout design and fabrication of a superjunction device are disclosed. A layout of active cell column structures can be configured so that a charge due to first conductivity type dopants balances out charge due to second conductivity type dopants in a doped layer in an active cell region. A layout of end portions of the active cell column structures proximate termination column structures can be configured so that a charge due to the first conductivity type dopants in the end portions and a charge due to the first conductivity type dopants in the termination column structures balances out charge due to the second conductivity type dopants in a portion of the doped layer between the termination column structures and the end portions. | 08-25-2011 |
20110278589 | Gallium Nitride Semiconductor Device With Improved Forward Conduction - A gallium nitride based semiconductor diode includes a substrate, a semiconductor body including a first heavily doped GaN layer and a second lightly doped GaN layer. The semiconductor body includes mesas projecting upwardly from a lower surface where each of the mesas includes the second GaN layer and a portion of the first GaN layer. Schottky contacts are formed on the upper surface of the mesas and ohmic contacts are formed on the lower surface of the semiconductor body. An insulating layer is formed over the Schottky and ohmic contacts. Vias are formed in the insulating layer to the Schottky contacts and vias are formed in the semiconductor body to the Ohmic contacts. An anode electrode is formed in a first metal pad in electrical contact with the Schottky contacts. A cathode electrode is formed in a second metal pad in electrical contact with the ohmic contacts. | 11-17-2011 |
20120282762 | Method For Forming Gallium Nitride Semiconductor Device With Improved Forward Conduction - A method for forming a gallium nitride based semiconductor diode includes forming Schottky contacts on the upper surface of mesas formed in a semiconductor body formed on a substrate. Ohmic contacts are formed on the lower surface of the semiconductor body. In one embodiment, an insulating layer is formed over the Schottky and ohmic contacts and vias are formed in the insulating layer to the Schottky and ohmic contacts to form the anode and cathode electrodes. In another embodiment, vias are formed in the insulating layer to the Schottky contacts and vias are formed in the semiconductor body to the ohmic contacts. An anode electrode is formed in electrical contact with the Schottky contacts. A cathode electrode is formed in electrical contact with the ohmic contacts on the backside of the substrate. | 11-08-2012 |
20130119393 | Vertical Gallium Nitride Schottky Diode - A vertical conduction nitride-based Schottky diode is formed using an insulating substrate which was lifted off after the diode device is encapsulated on the front side with a wafer level molding compound. The wafer level molding compound provides structural support on the front side of the diode device to allow the insulating substrate to be lifted off so that a conductive layer can be formed on the backside of the diode device as the cathode electrode. A vertical conduction nitride-based Schottky diode is thus realized. In another embodiment, a protection circuit for a vertical GaN Schottky diode employs a silicon-based vertical PN junction diode connected in parallel to the GaN Schottky diode to divert reverse bias avalanche current. | 05-16-2013 |
20130119394 | Termination Structure for Gallium Nitride Schottky Diode - A termination structure for a nitride-based Schottky diode includes a guard ring formed by an epitaxially grown P-type nitride-based compound semiconductor layer and dielectric field plates formed on the guard ring. The termination structure is formed at the edge of the anode electrode of the Schottky diode and has the effect of reducing electric field crowding at the anode electrode edge, especially when the Schottky diode is reverse biased. In one embodiment, the P-type epitaxial layer includes a step recess to further enhance the field spreading effect of the termination structure. | 05-16-2013 |
20130277740 | CORNER LAYOUT FOR SUPERJUNCTION DEVICE - A superjunction device and methods for layout design and fabrication of a superjunction device are disclosed. A layout of active cell column structures can be configured so that a charge due to first conductivity type dopants balances out charge due to second conductivity type dopants in a doped layer in an active cell region. A layout of end portions of the active cell column structures proximate termination column structures can be configured so that a charge due to the first conductivity type dopants in the end portions and a charge due to the first conductivity type dopants in the termination column structures balances out charge due to the second conductivity type dopants in a portion of the doped layer between the termination column structures and the end portions. | 10-24-2013 |
20140175451 | NORMALLY OFF GALLIUM NITRIDE FIELD EFFECT TRANSISTORS (FET) - A heterostructure field effect transistor (HFET) gallium nitride (GaN) semiconductor power device comprises a hetero-junction structure comprises a first semiconductor layer interfacing it second semiconductor layer of two different band gaps thus generating an interface layer as a two-dimensional electron gas (2DEG) layer. The power device further comprises a source electrode and a drain electrode disposed on two opposite sides of a gate electrode disposed on top of the hetero-junction structure for controlling a current flow between the source and drain electrodes in the 2DEG layer. The power device further includes a floating gate located between the gate electrode an hetero-junction structure, wherein the gate electrode is insulated from the floating gate with an insulation layer and wherein the floating gate is disposed above and padded with a thin insulation layer from the hetero-junction structure and wherein the floating gate is charged for continuously applying a voltage to the 2DEG layer to pinch off the current flowing in the 2DEG layer between the source and drain electrodes whereby the HFET semiconductor power device is a normally off device. | 06-26-2014 |
20140252372 | VERTICAL GALLIUM NITRIDE SCHOTTKY DIODE - A vertical conduction nitride-based Schottky diode is formed using an insulating substrate which was lifted off after the diode device is encapsulated on the front side with a wafer level molding compound. The wafer level molding compound provides structural support on the front side of the diode device to allow the insulating substrate to be lifted off so that a conductive layer can be formed on the backside of the diode device as the cathode electrode. A vertical conduction nitride-based Schottky diode is thus realized. In another embodiment, a protection circuit for a vertical GaN Schottky diode employs a silicon-based vertical PN junction diode connected in parallel to the GaN Schottky diode to divert reverse bias avalanche current. | 09-11-2014 |
20140273417 | METHOD FOR FORMING TERMINATION STRUCTURE FOR GALLIUM NITRIDE SCHOTTKY DIODE - A termination structure for a nitride-based Schottky diode includes a guard ring formed by an epitaxially grown P-type nitride-based compound semiconductor layer and dielectric field plates formed on the guard ring. The termination structure is formed at the edge of the anode electrode of the Schottky diode and has the effect of reducing electric field crowding at the anode electrode edge, especially when the Schottky diode is reverse biased. In one embodiment, the P-type epitaxial layer includes a step recess to further enhance the field spreading effect of the termination structure. | 09-18-2014 |