Patent application number | Description | Published |
20090140389 | NITRIDE SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A nitride semiconductor device with a p electrode having no resistance between itself and other electrodes, and a method of manufacturing the same are provided. A p electrode is formed of a first Pd film, a Ta film, and a second Pd film, which is an antioxidant film for preventing oxidation of the Ta film, and on a p-type contact layer of a nitride semiconductor. On the second Pd film, a pad electrode is formed. The second Pd film as an antioxidant film is formed on the entire upper surface of the Ta film which forms the p electrode, to prevent oxidation of the Ta film. This inhibits the resistance between the p electrode and the pad electrode, thereby preventing a failure in contact between the p electrode and the pad electrode and providing the low-resistance p electrode. | 06-04-2009 |
20090142871 | METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE - A method of manufacturing a semiconductor device provides a semiconductor device with a gallium-nitride-based semiconductor structure that allows long-term stable operation without degradation in device performance. After formation of an insulation film on a surface other than on a ridge surface, an oxygen-containing gas such as O | 06-04-2009 |
20090160054 | NITRIDE SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A nitride semiconductor device is provided which reduces the contact resistance at the interface between a P-type electrode and a nitride semiconductor layer. A nitride semiconductor device includes a P-type nitride semiconductor layer and a P-type electrode formed on the P-type nitride semiconductor layer. The P-type electrode is formed by successive laminations of a metal layer of a metal having a work function of 5.1 eV or more, a Pd layer of palladium, and a Ta layer of tantalum on the P-type nitride semiconductor layer. | 06-25-2009 |
20090170304 | METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE - A method of manufacturing a semiconductor device is provided, which can reduce the contact resistance of an ohmic electrode to a p-type nitride semiconductor layer and can achieve long-term stable operation. In forming, in an electrode forming step, a p-type ohmic electrode of a metal film by successive lamination of a Pd film which is a first p-type ohmic electrode and a Ta film which is a second p-type ohmic electrode on a p-type GaN contact layer, the metal film is formed to include an oxygen atom. In the presence of an oxygen atom in the metal film, then in a heat-treatment step, the p-type ohmic electrode of the metal film is heat-treated in an atmosphere that contains no oxygen atom-containing gas. | 07-02-2009 |
20090250705 | SILICON CARBIDE SEMICONDUCTOR DEVICE COMPRISING SILICON CARBIDE LAYER AND METHOD OF MANUFACTURING THE SAME - A p base ohmic contact of a silicon carbide semiconductor device consists of a p++ layer formed by high-concentration ion implantation and a metal electrode. Since the high-concentration ion implantation performed at the room temperature significantly degrades the crystal of the p++ layer to cause a process failure, a method for implantation at high temperatures is used. In terms of switching loss and the like of devices, it is desirable that the resistivity of the p base ohmic contact should be lower. In well-known techniques, nothing is mentioned on a detailed relation among the ion implantation temperature, the ohmic contact resistivity and the process failure. Then, in the ion implantation step, the temperature of a silicon carbide wafer is maintained in a range from 175° C. to 300° C., more preferably in a range from 175° C. to 200° C. The resistivity of the p base ohmic contact using a p++ region formed by ion implantation at a temperature in a range from 175° C. to 300° C. becomes lower than that in a case where the p++ region is formed by ion implantation at a temperature over 300° C. Further, this can avoid any process failure. | 10-08-2009 |
20090261348 | SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD - In a semiconductor device using a SiC substrate, a Junction Termination Edge (JTE) layer is hardly affected by fixed charge so that a stable dielectric strength is obtained. A semiconductor device according to a first aspect of the present invention includes a SiC epi-layer having n type conductivity, an impurity region in a surface of the SiC epi-layer and having p type conductivity, and JTE layers adjacent to the impurity region, having p type conductivity, and having a lower impurity concentration than the impurity region. The JTE layers are spaced by a distance from an upper surface of the SiC epi-layer, and SiC regions having n type conductivity are present on the JTE layers. | 10-22-2009 |
20100314629 | SILICON CARBIDE SEMICONDUCTOR DEVICE - In order to obtain a silicon carbide semiconductor device that ensures both stability of withstand voltage and reliability in high-temperature operations in its termination end-portion provided for electric-field relaxation in the perimeter of a cell portion driven as a semiconductor element, the termination end-portion is provided with an inorganic protection film having high heat resistance that is formed on an exposed surface of a well region as a first region formed on a side of the cell portion, and an organic protection film having a high electrical insulation capability with a little influence by electric charges that is formed on a surface of an electric-field relaxation region formed in contact relation to an outer lateral surface of the well region and apart from the cell portion, and on an exposed surface of the silicon carbide layer. | 12-16-2010 |
20110095301 | SILICON CARBIDE SEMICONDUCTOR DEVICE - There was a problem that it was difficult to manufacture silicon carbide semiconductor devices with suppressed variations in characteristics without increasing the number of process steps. A silicon carbide semiconductor device according to the present invention includes an N type SiC substrate and an N type SiC epitaxial layer as a silicon carbide semiconductor substrate of a first conductivity type, a plurality of recesses intermittently formed in a surface of the N type SiC epitaxial layer, P type regions as second-conductivity-type semiconductor layers formed in the N type SiC epitaxial layer in the bottoms of the plurality of recesses, and a Schottky electrode selectively formed over the surface of the N type SiC epitaxial layer, wherein the plurality of recesses all have an equal depth. | 04-28-2011 |
20110193100 | SIC SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A method of manufacturing an SiC semiconductor device according to the present invention includes the steps of (a) by using a single mask, etching regions of an SiC semiconductor layer which serve as an impurities implantation region and a mark region, to form recesses, (b) by using the same mask as in the step (a), performing ion-implantation in the recesses of the regions which serve as the impurities implantation region and the mark region, at least from an oblique direction relative to a surface of the SiC semiconductor layer and (c) positioning another mask based on the recess of the region which serves as the impurities implantation region or the mark region, and performing well implantation in a region containing the impurities implantation region. | 08-11-2011 |
20110195563 | METHOD OF MANUFACTURING SILICON CARBIDE SEMICONDUCTOR DEVICE - A method of manufacturing a silicon carbide semiconductor device according to the present invention includes the steps of (a) forming an implantation mask made up of a plurality of unit masks on a silicon carbide semiconductor layer, and (b) implanting predetermined ion in the silicon carbide semiconductor layer at a predetermined implantation energy by using the implantation mask. In the step (a), the implantation mask is formed such that a length from any point in the unit mask to an end of the unit mask can be equal to or less than a scattering length obtained when the predetermined ion is implanted in silicon carbide at the predetermined implantation energy and the implantation mask can have a plurality of regions different from each other in terms of a size and an arrangement interval of the unit masks. | 08-11-2011 |
20110223694 | METHOD OF MANUFACTURING SILICON CARBIDE SEMICONDUCTOR DEVICE - A wafer WF is mounted in a substrate holder, and the substrate holder is placed in a film forming furnace. The film forming furnace is evacuated by a vacuum pump through a gas discharge part to remove remaining oxygen as completely as possible. Then, a temperature in the film forming furnace is heated to a range of 800° C. to 950° C. under reduced pressure while an inert gas such as Ar or helium (He) is being introduced through a gas introduction part. When the temperature reaches this temperature range, an inflow of the inert gas is stopped. Vaporized ethanol is introduced as a source gas into the film forming furnace through the gas introduction part, thus forming a graphite film on an entire surface of the wafer WF. | 09-15-2011 |
20120112266 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - A semiconductor device of the present invention includes: a semiconductor substrate of a first conductive type; an epitaxial layer of the first conductive type formed on the semiconductor substrate and having a protrusion formed on a surface thereof; a well region of a second conductive type formed on the surface of the epitaxial layer at each side of the protrusion; a source region of the first conductive type selectively formed in a surface of the well region; a gate insulating film formed so as to cover at least the protrusion and the surface of the well region; and a gate electrode formed on a part of the gate insulating film corresponding to the protrusion. The gate insulating film is thicker in a region thereof corresponding to an upper surface of the protrusion than the other regions thereof. | 05-10-2012 |
20120132912 | SEMICONDUCTOR DEVICE - A MOSFET cell of a semiconductor device includes a polysilicon gate electrode and an n | 05-31-2012 |
20120132924 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREFOR - In the manufacture of a silicon carbide semiconductor device having a termination region being a JTE region or FLR, the margin of the amount of etching for removing a damage layer formed in the surface of the termination region is enlarged. A silicon carbide semiconductor device has a termination region being a JTE (Junction Termination Extension) region or an FLR (Field Limiting Ring) at a termination of the semiconductor elements. The termination region is formed by one step of ion implantation in which the kind of impurity and the implant energy are fixed. In the impurity concentration profile of the termination region in the depth direction, the concentration peak in the shallowest position is in a position deeper than 0.35 μm from the surface, and the concentration in the surface portion is not more than one-tenth of the shallowest concentration peak. | 05-31-2012 |
20120302051 | MANUFACTURING METHOD OF SILICON CARBIDE SEMICONDUCTOR DEVICE - A silicon oxide film is formed on an epitaxial layer by dry thermal oxidation, an ohmic electrode is formed on a back surface of a SiC substrate, an ohmic junction is formed between the ohmic electrode and the back surface of the SiC substrate by annealing the SiC substrate, the silicon oxide film is removed, and a Schottky electrode is formed on the epitaxial layer. Then, a sintering treatment is performed to form a Schottky junction between the Schottky electrode and the epitaxial layer. | 11-29-2012 |
20130026494 | SILICON CARBIDE SEMICONDUCTOR DEVICE - An SiC semiconductor device includes a semiconductor element formed in an SiC substrate, a source electrode and a gate pad formed by using an interconnect layer having barrier metal provided at the bottom surface thereof, and a temperature measuring resistive element formed by using part of the barrier metal in the interconnect line. | 01-31-2013 |
20130237043 | SiC SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A method of manufacturing an SiC semiconductor device according to the present invention includes the steps of (a) by using a single mask, etching regions of an SiC semiconductor layer which serve as an impurities implantation region and a mark region, to form recesses, (b) by using the same mask as in the step (a), performing ion-implantation in the recesses of the regions which serve as the impurities implantation region and the mark region, at least from an oblique direction relative to a surface of the SiC semiconductor layer and (c) positioning another mask based on the recess of the region which serves as the impurities implantation region or the mark region, and performing well implantation in a region containing the impurities implantation region. | 09-12-2013 |
20130309851 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREFOR - In the manufacture of a silicon carbide semiconductor device having a termination region being a JTE region or FLR, the margin of the amount of etching for removing a damage layer formed in the surface of the termination region is enlarged. A silicon carbide semiconductor device has a termination region being a JTE (Junction Termination Extension) region or an FLR (Field Limiting Ring) at a termination of the semiconductor elements. The termination region is formed by one step of ion implantation in which the kind of impurity and the implant energy are fixed. In the impurity concentration profile of the termination region in the depth direction, the concentration peak in the shallowest position is in a position deeper than 0.35 μm from the surface, and the concentration in the surface portion is not more than one-tenth of the shallowest concentration peak. | 11-21-2013 |
20140038397 | MANUFACTURING METHOD OF SILICON CARBIDE SEMICONDUCTOR DEVICE - A silicon oxide film is formed on an epitaxial layer by dry thermal oxidation, an ohmic electrode is formed on a back surface of a SiC substrate, an ohmic junction is formed between the ohmic electrode and the back surface of the SiC substrate by annealing the SiC substrate, the silicon oxide film is removed, and a Schottky electrode is formed on the epitaxial layer. Then, a sintering treatment is performed to form a Schottky junction between the Schottky electrode and the epitaxial layer. | 02-06-2014 |
20140077226 | SILICON CARBIDE SEMICONDUCTOR DEVICE - A silicon carbide semiconductor device of the present invention comprises a silicon carbide drift layer formed on a silicon carbide substrate, a P-type region formed in a surface layer of the silicon carbide drift layer, and a Schottky electrode formed above the silicon carbide drift layer correspondingly to a forming portion of the P-type region. The P-type region is formed of a plurality of unit cells arranged therein. Each of the unit cells has at least a first distribution region in which the P-type impurity is distributed at first concentration and a second distribution region in which the P-type impurity is distributed at second concentration higher than the first concentration. With this structure, it is possible to provide a silicon carbide semiconductor device in which a sufficient breakdown voltage can be achieved with less number of ion implantations. | 03-20-2014 |
20140191251 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - It is expected that both reduction of the resistance of a source region and reduction of a leakage current in a gate oxide film be achieved in an MOSFET in a silicon carbide semiconductor device. A leakage current to occur in a gate oxide film of the MOSFET is suppressed by reducing roughness at an interface between a source region and the gate oxide film. If an impurity concentration is to become high at a surface portion of the source region, the gate oxide film is formed by dry oxidation or CVD process. If the gate oxide film is formed by wet oxidation, the impurity concentration at the surface portion of the source region is controlled at a low level. | 07-10-2014 |
20140210008 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A semiconductor device includes an n-type drift layer formed on a main surface of a semiconductor substrate, a plurality of p-type well regions formed selectively in an upper layer portion of the drift layer, an n-type source region formed in a surface of the p-type well region, and a p-type contact region which is shallower than the source region formed in the surface of the p-type well region adjacent to the source region. Moreover, the semiconductor device includes an n-type additional region formed in contact with a bottom surface of the p-type well region in a position corresponding to below the contact region and deeper than the p-type well region. | 07-31-2014 |
20140242815 | METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE - A method of manufacturing a semiconductor device according to the present invention includes the steps of (b) forming, on a back face of a dummy substrate and back faces of a plurality of semiconductor substrates, inorganic films having such thicknesses as to be resistant to a temperature of a thermal oxidizing treatment or a heat treatment and to sufficiently decrease an amount of oxidation or reducing gaseous species to reach the back faces of the dummy substrate and the plurality of semiconductor substrates, (c) disposing the dummy substrate and the plurality of semiconductor substrates in a lamination with surfaces turned in the same direction at an interval from each other, and (d) carrying out a thermal oxidizing treatment or post annealing over the surfaces of the semiconductor substrates in an oxidation gas atmosphere or a reducing gas atmosphere after the steps (b) and (c). | 08-28-2014 |
20150014705 | SEMICONDUCTOR DEVICE - An optical fiber is provided between a photodiode and a semiconductor active portion of a wide gap semiconductor element forming portion such that emitted light at the time of light emission of the semiconductor active portion of the wide gap semiconductor element forming portion is incident from an incident surface of the optical fiber, and is received from an emitting surface to the photodiode through the optical fiber. Specifically, the incident surface of the optical fiber is arranged so as to be opposed to a side surface portion of the wide gap semiconductor element forming portion, so that the emitted light at the time of light emission of the wide gap semiconductor element is incident on the incident surface. | 01-15-2015 |
20150060882 | SILICON CARBIDE SEMICONDUCTOR DEVICE - A silicon carbide semiconductor device includes: a drift layer of the a first conduction type; a guard ring region of a second conduction type formed in annular form in a portion of one surface of the drift layer; a field insulating film formed on the one surface of the drift layer and surrounding the guard ring region; a Schottky electrode covering the guard ring region and the drift layer exposed inside the guard ring region and having an outer peripheral end existing on the field insulating film; and a surface electrode pad on the Schottky electrode, wherein an outer peripheral end of the surface electrode pad comes into contact with the field insulating film over the outer peripheral end of the Schottky electrode. | 03-05-2015 |