Patent application number | Description | Published |
20080239817 | Nonvolatile semiconductor memory device and method of erasing and programming the same - A nonvolatile semiconductor memory device includes a semiconductor substrate having a source, a drain, and a channel region between the source and the drain. The channel region has a first end portion near the drain, a second end portion near the source, and a middle portion between the first and second end portions. The first and second end portions having approximately same width. The memory device is electrically erased by using a hot carrier generated in the first end portion due to avalanche breakdown. The channel region includes a first channel extending from the drain and a second channel adjacent to the first channel. An impurity concentration of the second channel is higher than that of the first channel. An interface between the first and second channels is located in the middle portion between the first and second end portions. | 10-02-2008 |
20090230405 | Diode having Schottky junction and PN junction and method for manufacturing the same - A manufacturing method of a diode includes: forming a P type semiconductor film on a N type semiconductor layer with a crystal growth method; forming a first metallic film on the P type semiconductor film so that the first metallic film contacts the P type semiconductor film with an ohmic contact; forming a mask having an opening on the first metallic film; etching a part of the first metallic film and a part of the P type semiconductor film via the opening so that a part of the N type semiconductor layer is exposed; and forming a second metallic film on the part of the N type semiconductor layer so that the second metallic film contacts the N type semiconductor layer with a Schottky contact. | 09-17-2009 |
20100032730 | Semiconductor device and method of making the same - A method of making a semiconductor device includes forming a p-type semiconductor region to an n-type semiconductor substrate in such a manner that the p-type semiconductor region is partially exposed to a top surface of the semiconductor substrate, forming a Schottky electrode of a first material in such a manner that the Schottky electrode is in Schottky contact with an n-type semiconductor region exposed to the top surface of the semiconductor substrate, and forming an ohmic electrode of a second material different from the first material in such a manner that the ohmic electrode is in ohmic contact with the exposed p-type semiconductor region. The Schottky electrode is formed earlier than the ohmic electrode. | 02-11-2010 |
20100244049 | Silicon carbide semiconductor device with schottky barrier diode and method of manufacturing the same - A silicon carbide semiconductor device with a Schottky barrier diode includes a first conductivity type silicon carbide substrate, a first conductivity type silicon carbide drift layer on a first surface of the substrate, a Schottky electrode forming a Schottky contact with the drift layer, and an ohmic electrode on a second surface of the substrate. The Schottky electrode includes an oxide layer in direct contact with the drift layer. The oxide layer is made of an oxide of molybdenum, titanium, nickel, or an alloy of at least two of these elements. | 09-30-2010 |
20110203513 | METHOD OF MANUFACTURING SILICON CARBIDE SUBSTRATE - In a method of manufacturing a silicon carbide substrate, a defect-containing substrate made of silicon carbide is prepared. The defect-containing substrate has a front surface, a rear surface being opposite to the front surface, and a surface portion adjacent to the front surface. The detect-containing substrate includes a screw dislocation in the surface portion. The front surface of the defect-containing substrate is applied with an external force so that a crystallinity of the surface portion is reduced. After being applied with the external force, the defect-containing substrate is thermally treated so that the crystallinity of the surface portion is recovered. | 08-25-2011 |
20110204383 | SIC SEMICONDUCTOR DEVICE HAVING SCHOTTKY BARRIER DIODE AND METHOD FOR MANUFACTURING THE SAME - A SiC semiconductor device having a Schottky barrier diode includes: a substrate made of SiC and having a first conductive type, wherein the substrate includes a main surface and a rear surface; a drift layer made of SiC and having the first conductive type, wherein the drift layer is disposed on the main surface of the substrate and has an impurity concentration lower than the substrate; a Schottky electrode disposed on the drift layer and has a Schottky contact with a surface of the drift layer; and an ohmic electrode disposed on the rear surface of the substrate. The Schottky electrode directly contacts the drift layer in such a manner that a lattice of the Schottky electrode is matched with a lattice of the drift layer. | 08-25-2011 |
20110291110 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - The silicon carbide semiconductor device includes a substrate, a drift layer, a base region, a source region, a trench, a gate insulating layer, a gate electrode, a source electrode, a drain electrode, and a deep layer. The deep layer is disposed under the base region and is located to a depth deeper than the trench. The deep layer is divided into a plurality of portions in a direction that crosses a longitudinal direction of the trench. The portions include a group of portions disposed at positions corresponding to the trench and arranged at equal intervals in the longitudinal direction of the trench. The group of portions surrounds corners of a bottom of the trench. | 12-01-2011 |
20110309464 | SEMICONDUCTOR DEVICE INCLUDING CELL REGION AND PERIPHERAL REGION HAVING HIGH BREAKDOWN VOLTAGE STRUCTURE - A semiconductor device includes a semiconductor substrate and an electric field terminal part. The semiconductor substrate includes a substrate, a drift layer disposed on a surface of the substrate, and a base layer disposed on a surface of the drift layer. The semiconductor substrate is divided into a cell region in which a semiconductor element is disposed and a peripheral region that surrounds the cell region. The base region has a bottom face located on a same plane throughout the cell region and the peripheral region and provides an electric field relaxing layer located in the peripheral region. The electric field terminal part surrounds the cell region and a portion of the electric field relaxing layer and penetrates the electric field relaxing layer from a surface of the electric field relaxing layer to the drift layer. | 12-22-2011 |
20120012860 | SIC SEMICONDUCTOR DEVICE - A SiC semiconductor device includes a reverse type MOSFET having: a substrate; a drift layer and a base region on the substrate; a base contact layer and a source region on the base region; multiple trenches having a longitudinal direction in a first direction penetrating the source region and the base region; a gate electrode in each trench via a gate insulation film; an interlayer insulation film covering the gate electrode and having a contact hole, through which the source region and the base contact layer are exposed; a source electrode coupling with the source region and the base region through the contact hole; a drain electrode on the substrate. The source region and the base contact layer extend along with a second direction perpendicular to the first direction, and are alternately arranged along with the first direction. The contact hole has a longitudinal direction in the first direction. | 01-19-2012 |
20120061682 | SIC SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - A SiC semiconductor device includes: a substrate, a drift layer, and a base region stacked in this order; first and second source regions and a contact layer in the base region; a trench penetrating the source and base regions; a gate electrode in the trench; an interlayer insulation film with a contact hole covering the gate electrode; a source electrode coupling with the source region and the contact layer via the contact hole; a drain electrode on the substrate; and a metal silicide film. The high concentration second source region is shallower than the low concentration first source region, and has a part covered with the interlayer insulation film, which includes a low concentration first portion near a surface and a high concentration second portion deeper than the first portion. The metal silicide film on the second part has a thickness larger than the first portion. | 03-15-2012 |
20120142173 | MANUFACTURING METHOD OF SILICON CARBIDE SINGLE CRYSTAL - A manufacturing method of an SiC single crystal includes preparing an SiC substrate, implanting ions into a surface portion of the SiC substrate to form an ion implantation layer, activating the ions implanted into the surface portion of the SiC substrate by annealing, chemically etching the surface portion of the SiC substrate to form an etch pit that is caused by a threading screw dislocation included in the SiC substrate and performing an epitaxial growth of SiC to form an SiC growth layer on a surface of the SiC substrate including an inner wall of the etch pit in such a manner that portions of the SiC growth layer grown on the inner wall of the etch pit join with each other. | 06-07-2012 |
20120161154 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME - An SiC semiconductor device includes a substrate, a drift layer, a base region, a source region, a trench, a gate oxide film, a gate electrode, a source electrode and a drain electrode. The substrate has a Si-face as a main surface. The source region has the Si-face. The trench is provided from a surface of the source region to a portion deeper than the base region and extends longitudinally in one direction and has a Si-face bottom. The trench has an inverse tapered shape, which has a smaller width at an entrance portion than at a bottom, at least at a portion that is in contact with the base region. | 06-28-2012 |
20120181551 | SILICON CARBIDE SEMICONDUCTOR DEVICE - A silicon carbide semiconductor device includes a silicon carbide semiconductor substrate and a trench. The silicon carbide semiconductor substrate has an offset angle with respect to a ( | 07-19-2012 |
20120273801 | SILICON CARBIDE SEMICONDUCTOR DEVICE - A SiC semiconductor device includes: a SiC substrate including a first or second conductive type layer and a first conductive type drift layer and including a principal surface having an offset direction; a trench disposed on the drift layer and having a longitudinal direction; and a gate electrode disposed in the trench via a gate insulation film. A sidewall of the trench provides a channel formation surface. The vertical semiconductor device flows current along with the channel formation surface of the trench according to a gate voltage applied to the gate electrode. The offset direction of the SiC substrate is perpendicular to the longitudinal direction of the trench. | 11-01-2012 |
20120319136 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - A SiC device includes an inversion type MOSFET having: a substrate, a drift layer, and a base region stacked in this order; source and contact regions in upper portions of the base region; a trench penetrating the source and base regions; a gate electrode on a gate insulating film in the trench; a source electrode coupled with the source and base region; a drain electrode on a back of the substrate; and multiple deep layers in an upper portion of the drift layer deeper than the trench. Each deep layer has an impurity concentration distribution in a depth direction, and an inversion layer is provided in a portion of the deep layer on the side of the trench under application of the gate voltage. | 12-20-2012 |
20130001592 | SILICON CARBIDE SEMICONDUCTOR DEVICE - In a silicon carbide semiconductor device, a plurality of trenches has a longitudinal direction in one direction and is arranged in a stripe pattern. Each of the trenches has first and second sidewalls extending in the longitudinal direction. The first sidewall is at a first acute angle to one of a (11-20) plane and a (1-100) plane, the second sidewall is at a second acute angle to the one of the (11-20) plane and the (1-100) plane, and the first acute angle is smaller than the second acute angle. A first conductivity type region is in contact with only the first sidewall in the first and second sidewalls of each of the trenches, and a current path is formed on only the first sidewall in the first and second sidewalls. | 01-03-2013 |
20140175459 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - A SiC semiconductor device includes: a semiconductor switching element having: a substrate, a drift layer and a base region stacked in this order; a source region and a contact region in the base region; a trench extending from a surface of the source region to penetrate the base region; a gate electrode on a gate insulating film in the trench; a source electrode electrically coupled with the source region and the base region; a drain electrode on a back side of the substrate; and multiple deep layers in an upper portion of the drift layer deeper than the trench. Each deep layer has upper and lower portions. A width of the upper portion is smaller than the lower portion. | 06-26-2014 |
20140175508 | SEMICONDUCTOR DEVICE WITH SCHOTTKY BARRIER DIODE - A semiconductor device includes a first conductivity-type drift region including an exposed portion, a plurality of second conductivity-type body regions, a first conductivity-type source region, a gate portion and a Schottky electrode. The drift region is defined in a semiconductor layer, and the exposed portion exposes on a surface of the semiconductor layer. The body regions are disposed on opposite sides of the exposed portion. The source region is separated from the drift region by the body region. The gate portion is disposed to oppose the body region. The exposed portion is formed with a groove, and the Schottky electrode is disposed in the groove. The Schottky electrode has a Schottky contact with the exposed portion. | 06-26-2014 |
20150048382 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - In a silicon carbide semiconductor device, a p-type SiC layer is disposed in a corner of a bottom of a trench. Thus, even if an electric field is applied between a drain and a gate when a MOSFET is turned off, a depletion layer in a pn junction between the p-type SiC layer and an n | 02-19-2015 |