Patent application number | Description | Published |
20090159896 | SILICON CARBIDE MOSFET DEVICES AND METHODS OF MAKING - A method of making a silicon carbide MOSFET is disclosed. The method includes providing a semiconductor device structure, wherein the device structure comprises a silicon carbide semiconductor device layer, an ion implanted well region of a first conductivity type formed in the semiconductor device layer, an ion implanted source region of a second conductivity type formed into the ion implanted well region; providing a mask layer over the semiconductor device layer, the mask layer exposing a portion of the ion implanted source region, then etching through the portion of the ion implanted source region to form a dimple; then implanting ions through the dimple to form a high dopant concentration first conductivity type ion implanted contact region, wherein the ion implanted contact region is deeper than the ion implanted well region; then removing the contact region mask layer and annealing implanted ions. | 06-25-2009 |
20090194772 | Method For Fabricating Silicon Carbide Vertical MOSFET Devices - A method of forming a vertical MOSFET device includes forming a first trench within a semiconductor layer of a first polarity, the first trench generally defining a well region of a second polarity opposite the first polarity; growing a first epitaxial well layer of the second polarity over the original semiconductor layer; growing a second epitaxial source contact layer of the first polarity over the well layer; forming a second trench through the source contact layer and at least a portion of the well layer; growing a third epitaxial layer of the second polarity over the source contact layer; and planarizing at least the first and second epitaxial layers so as to expose an upper surface of the original semiconductor layer, wherein a top surface of the third epitaxial layer is substantially coplanar with a top surface of the source contact layer prior to ohmic contact formation. | 08-06-2009 |
20090242901 | SiC MOSFETS AND SELF-ALIGNED FABRICATION METHODS THEREOF - The present invention provides a method of fabricating a metal oxide semiconductor field effect transistor. The method includes the steps of forming a source region on a silicon carbide layer and annealing the source region. A gate oxide layer is formed on the source region and the silicon carbide layer. The method further includes providing a gate electrode on the gate oxide layer and disposing a dielectric layer on the gate electrode and the gate oxide layer. The method further includes etching a portion of the dielectric layer and a portion of the gate oxide layer to form sidewalls on the gate electrode. A metal layer is disposed on the gate electrode, the sidewalls and the source region. The method further includes forming a gate contact and a source contact by subjecting the metal layer to a temperature of at least about 800° C. The gate contact and the source contact comprise a metal silicide. The distance between the gate contact and the source contact is less than about 0.6 μm. A vertical SiC MOSFET is also provided. | 10-01-2009 |
20090267141 | METHOD FOR FABRICATING SILICON CARBIDE VERTICAL MOSFET DEVICES - A method of forming a vertical MOSFET device includes forming a trench within a drift layer substrate, the drift layer comprising a first polarity type, the trench generally defining a well region of a second polarity type opposite the first polarity type. An ohmic contact layer is formed within a bottom surface of the trench, the ohmic contact layer comprising a material of the second polarity type. A layer of the second polarity type is epitaxially grown over the drift layer, sidewall surfaces of the trench, and the ohmic contact layer. A layer of the first polarity type is epitaxially grown over the epitaxially grown layer of the second polarity type so as to refill the trench, and the epitaxially grown layers of the first and second polarity type are planarized so as to expose an upper surface of the drift layer substrate. | 10-29-2009 |
20100200931 | MOSFET DEVICES AND METHODS OF MAKING - A MOSFET device and a method for fabricating MOSFET devices are disclosed. The method includes providing a semiconductor device structure including a semiconductor device layer of a first conductivity type, and ion implanting a well structure of a second conductivity type in the semiconductor device layer, where the ion implanting includes providing a dopant concentration profile in a single mask implant sequence. | 08-12-2010 |
20120153362 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A method comprising, introducing a dopant type into a semiconductor layer to define a well region of the semiconductor layer, the well region comprising a channel region, and introducing a dopant type into the well region to define a multiple implant region substantially coinciding with the well region but excluding the channel region. | 06-21-2012 |
20130126971 | SILICON-CARBIDE MOSFET CELL STRUCTURE AND METHOD FOR FORMING SAME - In one embodiment, the invention comprises a MOSFET comprising individual MOSFET cells. Each cell comprises a U-shaped well (P type) and two parallel sources (N type) formed within the well. A Number of source rungs (doped N) connect sources at multiple locations. Regions between two rungs comprise a body (P type). These features are formed on an N-type epitaxial layer, which is formed on an N-type substrate. A contact extends across and contacts a number of source rungs and bodies. Gate oxide and a gate contact overlie a leg of a first well and a leg of a second adjacent well, inverting the conductivity responsive to a gate voltage. A MOSFET comprises a plurality of these cells to attain a desired low channel resistance. The cell regions are formed using self-alignment techniques at several states of the fabrication process. | 05-23-2013 |
20130146898 | SiC MOSFETS AND SELF-ALIGNED FABRICATION METHODS THEREOF - The present application provides a method of fabricating a metal oxide semiconductor field effect transistor. The method includes the steps of forming a source region on a silicon carbide layer and annealing the source region. A gate oxide layer is formed on the source region and the silicon carbide layer. The method further includes providing a gate electrode on the gate oxide layer and disposing a dielectric layer on the gate electrode and the gate oxide layer. The method further includes etching a portion of the dielectric layer and a portion of the gate oxide layer to form sidewalls on the gate electrode. A metal layer is disposed on the gate electrode, the sidewalls and the source region. The method further includes forming a gate contact and a source contact by subjecting the metal layer to a temperature of at least about 800° C. The gate contact and the source contact comprise a metal silicide. The distance between the gate contact and the source contact is less than about 0.6 μm. A vertical SiC MOSFET is also provided. | 06-13-2013 |
20130334612 | INTEGRATED CIRCUIT AND METHOD OF FABRICATING SAME - An integrated circuit includes a plurality of transistors. Each transistor is associated with a corresponding body terminal. At least one transistor is reverse biased at a first voltage level, and at least one other transistor is reverse biased at a second voltage level that is different from the first voltage level. Each body terminal is electrically isolated from every other body terminal via an isolation barrier. A transistor that is reverse biased at the first voltage level is electrically connected to a transistor that is reverse biased at the second voltage level, such that the electrically connected transistors operate to interact with each other while the respective body voltage levels are different from each other and are changing independently of each other during operation of the integrated circuit. | 12-19-2013 |
20140070229 | SYSTEMS AND METHODS FOR TERMINATING JUNCTIONS IN WIDE BANDGAP SEMICONDUCTOR DEVICES - An electrical device includes a blocking layer disposed on top of a substrate layer, wherein the blocking layer and the substrate layer each are wide bandgap semiconductors, and the blocking layer and the substrate layer form a buried junction in the electrical device. The device comprises a termination feature disposed at a surface of the blocking layer and a filled trench disposed proximate to the termination feature. The filled trench extends through the blocking layer to reach the substrate layer and is configured to direct an electrical potential associated with the buried junction toward the termination feature disposed near the surface of the blocking layer to terminate the buried junction. | 03-13-2014 |
20140167068 | SYSTEMS AND METHODS FOR OHMIC CONTACTS IN SILICON CARBIDE DEVICES - A silicon carbide device is presented that includes a gate electrode disposed over a portion of a silicon carbide substrate as well as a dielectric film disposed over the gate electrode. The device has a contact region disposed near the gate electrode and has a layer disposed over the dielectric film and over the contact region. The layer includes nickel in portions disposed over the dielectric film and includes nickel silicide in portions disposed over the contact region. The nickel silicide layer is configured to provide an ohmic contact to the contact region of the silicon carbide device. | 06-19-2014 |
20140361315 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A semiconductor device according to one embodiment having a first region comprising a first dopant type, a second region adjacent the first region haivng a second dopant type and a channel region. There is a third region segregated from the channel region having a second dopant type, wherein the third region substantially coincides with the second region. | 12-11-2014 |