| Patent application number | Description | Published |
|---|
| 20080197360 | Diode Having Reduced On-resistance and Associated Method of Manufacture - A diode structure having a reduced on-resistance in the forward-biased condition includes semiconductor layers, preferably of silicon carbide. The anode and cathode of the device are located on the same side of the bottom semiconductor layer, providing lateral conduction across the diode body. The anode is positioned on a semiconductor mesa, and the sides of the mesa are covered with a nonconductive spacer extending from the anode to the bottom layer. An ohmic contact, preferably a metal silicide, covers the surface of the bottom layer between the spacer material and the cathode. The conductive path extends from anode to cathode through the body of the mesa and across the bottom semiconductor layer, including the ohmic contact. The method of forming the diode includes reacting layers of silicon and metal on the appropriate regions of the diode to form an ohmic contact of metal silicide. | 08-21-2008 |
| 20090104738 | Method of Forming Vias in Silicon Carbide and Resulting Devices and Circuits - A method of fabricating an integrated circuit on a silicon carbide substrate is disclosed that eliminates wire bonding that can otherwise cause undesired inductance. The method includes fabricating a semiconductor device in epitaxial layers on a surface of a silicon carbide substrate and with at least one metal contact for the device on the uppermost surface of the epitaxial layer. The opposite surface of the substrate is then ground and polished until it is substantially transparent. The method then includes masking the polished surface of the silicon carbide substrate to define a predetermined location for at least one via that is opposite the device metal contact on the uppermost surface of the epitaxial layer and etching the desired via in steps. The first etching step etches through the silicon carbide substrate at the desired masked location until the etch reaches the epitaxial layer. The second etching step etches through the epitaxial layer to the device contacts. Finally, metallizing the via provides an electrical path from the first surface of the substrate to the metal contact and to the device on the second surface of the substrate. | 04-23-2009 |
| 20090215280 | Passivation of Wide Band-Gap Based Semiconductor Devices with Hydrogen-Free Sputtered Nitrides - A passivated semiconductor structure and associated method are disclosed. The structure includes a silicon carbide substrate or layer; an oxidation layer on the silicon carbide substrate for lowering the interface density between the silicon carbide substrate and the thermal oxidation layer; a first sputtered non-stoichiometric silicon nitride layer on the thermal oxidation layer for reducing parasitic capacitance and minimizing device trapping; a second sputtered non-stoichiometric silicon nitride layer on the first layer for positioning subsequent passivation layers further from the substrate without encapsulating the structure; a sputtered stoichiometric silicon nitride layer on the second sputtered layer for encapsulating the structure and for enhancing the hydrogen barrier properties of the passivation layers; and a chemical vapor deposited environmental barrier layer of stoichiometric silicon nitride for step coverage and crack prevention on the encapsulant layer. | 08-27-2009 |
| 20110108855 | METHOD OF FORMING VIAS IN SILICON CARBIDE AND RESULTING DEVICES AND CIRCUITS - A method of fabricating an integrated circuit on a silicon carbide substrate is disclosed that eliminates wire bonding that can otherwise cause undesired inductance. The method includes fabricating a semiconductor device including a Group III-V semiconductor layer on a surface on a silicon carbide substrate, wherein the semiconductor device defines at least one via through the silicon carbide substrate and the epitaxial layer. | 05-12-2011 |
| 20110165771 | METHOD OF FORMING VIAS IN SILICON CARBIDE AND RESULTING DEVICES AND CIRCUITS - A method of fabricating an integrated circuit on a silicon carbide substrate is disclosed that eliminates wire bonding. The method includes fabricating a semiconductor device in epitaxial layers on a surface of a silicon carbide substrate and with at least one metal contact for the device on the uppermost surface of the epitaxial layer. The opposite surface of the substrate is then ground and polished until it is substantially transparent. The polished surface of the silicon carbide substrate is then masked to define a predetermined location for at least one via that is opposite the device metal contact and etching the desired via in steps. The first etching step etches through the silicon carbide substrate at the desired masked location until the etch reaches the epitaxial layer. The second etching step etches through the epitaxial layer to the device contacts. Finally, the via is metallized. | 07-07-2011 |
