Patent application number | Description | Published |
20080203402 | SiC semiconductor device and method for manufacturing the same - A SiC semiconductor device includes: a SiC substrate having a main surface; a channel region on the substrate; first and second impurity regions on upstream and downstream sides of the channel region, respectively; a gate on the channel region through a gate insulating film. The channel region for flowing current between the first and second impurity regions is controlled by a voltage applied to the gate. An interface between the channel region and the gate insulating film has a hydrogen concentration equal to or greater than 2.6×10 | 08-28-2008 |
20080206941 | Method for manufacturing sic semiconductor device - A method for manufacturing a SiC semiconductor device includes: preparing a SiC substrate having a (11-20)-orientation surface; forming a drift layer on the substrate; forming a base region in the drift layer; forming a first conductivity type region in the base region; forming a channel region on the base region to couple between the drift layer and the first conductivity type region; forming a gate insulating film on the channel region; forming a gate electrode on the gate insulating film; forming a first electrode to electrically connect to the first conductivity type region; and forming a second electrode on a backside of the substrate. The device controls current between the first and second electrodes by controlling the channel region. The forming the base region includes epitaxially forming a lower part of the base region on the drift layer. | 08-28-2008 |
20080258152 | SiC semiconductor device having outer periphery structure - A SiC semiconductor device includes: a SiC substrate; a SiC drift layer on the substrate having an impurity concentration lower than the substrate; a semiconductor element in a cell region of the drift layer; an outer periphery structure including a RESURF layer in a surface portion of the drift layer and surrounding the cell region; and an electric field relaxation layer in another surface portion of the drift layer so that the electric field relaxation layer is separated from the RESURF layer. The electric field relaxation layer is disposed on an inside of the RESURF layer so that the electric field relaxation layer is disposed in the cell region. The electric field relaxation layer has a ring shape. | 10-23-2008 |
20080258153 | Silcon carbide semiconductor device having schottky barrier diode and method for manufacturing the same - An SiC semiconductor device is provided, which comprises: a substrate made of silicon carbide and having a principal surface; a drift layer made of silicon carbide and disposed on the principal surface; an insulating layer disposed on the drift layer and including an opening; a Schottky electrode contacting with the drift layer through the opening; a termination structure disposed around an outer periphery of the opening; and second conductivity type layers disposed in a surface part of the drift layer, contacting the Schottky electrode, surrounded by the termination structure, and separated from one another. The second conductivity type layers include a center member and ring members. Each ring member surrounds the center member and is arranged substantially in a point symmetric manner with respect to the center member. | 10-23-2008 |
20080277668 | SIS semiconductor having junction barrier schottky device - A semiconductor device having a junction barrier Schottky diode includes: a SiC substrate; a drift layer on the substrate; an insulation film on the drift layer having an opening in a cell region; a Schottky barrier diode having a Schottky electrode contacting the drift layer through the opening of the insulation film and an ohmic electrode on the substrate; a terminal structure having a RESURF layer surrounding the cell region; and multiple second conductive type layers on an inner side of the RESURF layer. The second conductive type layers and the drift layer provide a PN diode. The Schottky electrode includes a first Schottky electrode contacting the second conductive type layers with ohmic contact and a second Schottky electrode contacting the drift layer with Schottky contact. | 11-13-2008 |
20080277669 | SiC semiconductor having junction barrier Schottky device - A semiconductor device having a JBS diode includes: a SiC substrate; a drift layer on the substrate; an insulation film on the drift layer having an opening in a cell region; a Schottky barrier diode having a Schottky electrode contacting the drift layer through the opening and an ohmic electrode on the substrate; a terminal structure having a RESURF layer in the drift layer surrounding the cell region; and multiple second conductive type layers in the drift layer on an inner side of the RESURF layer contacting the Schottky electrode. The second conductive type layers are separated from each other. The second conductive type layers and the drift layer provide a PN diode. Each second conductive type layer has a depth larger than the RESURF layer. | 11-13-2008 |
20080283845 | Silicon carbide semiconductor device having high channel mobility and method for manufacturing the same - A silicon carbide semiconductor device having a MOS structure includes: a substrate; a channel area in the substrate; a first impurity area; a second impurity area; a gate insulating film on the channel area; and a gate on the gate insulating film. The channel area provides an electric current path. The channel area and the gate insulating film have an interface therebetween. The interface includes a dangling bond, which is terminated by a hydrogen atom or a hydroxyl. The interface has a hydrogen concentration equal to or larger than 2.6×10 | 11-20-2008 |
20080296587 | Silicon carbide semiconductor device having junction barrier schottky diode - A silicon carbide semiconductor device includes a substrate; a drift layer having a first conductivity type; an insulating layer; a Schottky electrode; an ohmic electrode; a resurf layer; and second conductivity type layers. The drift layer and the second conductivity type layers provide multiple PN diodes. Each second conductivity type layer has a radial width with respect to a center of a contact region between the Schottky electrode and the drift layer. A radial width of one of the second conductivity type layers is smaller than that of another one of the second conductivity type layers, which is disposed closer to the center of the contact region than the one of the second conductivity type layers. | 12-04-2008 |
20090008651 | Silicon carbide semiconductor device having junction barrier schottky diode - A silicon carbide semiconductor device includes a drift layer having first conductive type on a substrate, a cell region in the drift layer, a schottky electrode on the drift layer and multiple second conductive type layers in the cell region. The second conductive type layers are separated from each other and contact the schottky electrode. A size and an impurity concentration of the second conductive type layers and a size and an impurity concentration of a portion of the drift layer sandwiched between the second conductive type layers are determined so that a charge quantity of the second conductive type layers is equal to a charge quantity of the portion. Hereby, the pressure-proof JBS and low resistivity second conductive type layers arranged on a surface of the drift layer to provide a PN diode, can be obtained. | 01-08-2009 |
20090011598 | Method of manufacturing semiconductor device including silicon carbide substrate - In a manufacturing method of a silicon carbide semiconductor device, a silicon carbide substrate is prepared by slicing an ingot that is made of silicon carbide single crystal. The silicon carbide substrate is heat treated for exposing a substrate defect generated at a surface portion of the silicon carbide substrate and the surface portion of the silicon carbide substrate is chemical-mechanical polished in such a manner that the exposed substrate defect is removed. Then, a semiconductor element is formed on the silicon carbide substrate. | 01-08-2009 |
20090090920 | Silicon carbide semiconductor device - A silicon carbide semiconductor device is disclosed. The silicon carbide semiconductor device includes a substrate; a drift layer having a first conductivity type and located on a first surface of the substrate; and a vertical type semiconductor element. The vertical type semiconductor element includes: an impurity layer having a second conductivity type, and located in a surface portion of the drift layer; and a first conductivity type region located in the drift layer, spaced away from the impurity layer, located closer to the substrate than the impurity layer, and having an impurity concentration higher than the drift layer. | 04-09-2009 |
20090159898 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THEREOF - A semiconductor device is provided in which the contact resistance of the interface between an electrode and the semiconductor substrate is reduced. The semiconductor device includes a 4H polytype SiC substrate, and an electrode formed on a surface of the substrate. A 3C polytype layer, which extends obliquely relative to the surface of the substrate and whose end portion at the substrate surface is in contact with the electrode, is formed at the surface of the substrate. The 3C polytype layer has a lower bandgap than 4H polytype. Hence, electrons present in the 4H polytype region pass through the 3C polytype layer and reach the electrode. More precisely, the width of the passageway of the electrons is determined by the thickness of the 3C polytype layer. Consequently, with this semiconductor device, in which the passageway of the electrons is narrow, the electrons are able to reach the electrode at a speed close to the theoretical value, by the quantum wire effect. In this way, the contact resistance can be reduced in the semiconductor device. | 06-25-2009 |
20090166730 | SiC semiconductor device having bottom layer and method for manufacturing the same - A SiC semiconductor device includes: a substrate; a drift layer on the substrate; a trench on the drift layer; a base region in the drift layer sandwiching the trench; a channel between the base region and the trench; a source region in the base region sandwiching the trench via the channel; a gate electrode in the trench via a gate insulation film; a source electrode coupled with the source region; a drain electrode on the substrate opposite to the drift layer; and a bottom layer under the trench. An edge portion of the bottom layer under a corner of a bottom of the trench is deeper than a center portion of the bottom layer under a center portion of the bottom of the trench. | 07-02-2009 |
20090200559 | Silicon carbide semiconductor device including deep layer - A silicon carbide semiconductor device includes a substrate, a drift layer located on a first surface of the substrate, a base region located on the drift layer, a source region located on the base region, a trench penetrating the source region and the base region to the drift layer, a channel layer located in the trench, a gate insulating layer located on the channel layer, a gate electrode located on the gate insulating layer, a source electrode electrically coupled with the source region and the base region, a drain electrode located on a second surface of the substrate, and a deep layer. The deep layer is located under the base region, extends to a depth deeper than the trench and is formed along an approximately normal direction to a sidewall of the trench. | 08-13-2009 |
20090236611 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD OF MAKING THE SAME - A silicon carbide semiconductor device provided as a semiconductor chip includes a substrate, a drift layer on the substrate, an insulation film on the drift layer, a semiconductor element formed in a cell region of the drift layer, a surface electrode formed on the drift layer and electrically coupled to the semiconductor element through an opening of the insulation film, and a passivation film formed above the drift layer around the periphery of the cell region to cover an outer edge of the surface electrode. The passivation film has an opening through which the surface electrode is exposed outside. A surface of the passivation film is made uneven to increase a length from an inner edge of the opening of the passivation film to a chip edge measured along the surface of the passivation film. | 09-24-2009 |
20090261350 | Silicon carbide semiconductor device including deep layer - A silicon carbide semiconductor device includes a substrate, a drift layer located on a first surface of the substrate, a base region located on the drift layer, a source region located on the base region, a trench sandwiched by each of the base region to the drift layer, a channel layer located in the trench, a gate insulating layer located on the channel layer, a gate electrode located on the gate insulating layer, a source electrode electrically coupled with the source region and the base region, a drain electrode located on a second surface of the substrate, and a deep layer located under the base region and extending to a depth deeper than the trench. The deep layer is formed into a lattice pattern. | 10-22-2009 |
20090267082 | Semiconductor device and manufacturing method of the same - A semiconductor device includes: a semiconductor element having a first surface and a second surface; a first electrode disposed on the first surface of the element; a second electrode disposed on the second surface of the element; and an insulation film covers a part of the first electrode, the first surface of the element and a part of a sidewall of the element. The above semiconductor device has small dimensions and a high breakdown voltage. | 10-29-2009 |
20090280609 | Method of making silicon carbide semiconductor device - In a method of making a silicon carbide semiconductor device having a MOSFET, after a mask is placed on a surface of a first conductivity type drift layer of silicon carbide, ion implantation is performed by using the mask to form a lower layer of a deep layer extending in one direction. A first conductivity type current scattering layer having a higher concentration than the drift layer is formed on the surface of the drift layer. After another mask is placed on a surface of the current scattering layer, ion implantation is performed by using the other mask to form an upper layer of the deep layer at a position corresponding to the lower layer in such a manner that the lower layer and the upper layer are connected together. | 11-12-2009 |
20090289264 | Silicon carbide semiconductor device and method of manufacturing the same - An SiC semiconductor device includes a substrate, a drift layer disposed on a first surface of the substrate, a base region disposed above the drift layer, a source region disposed above the base region, a trench penetrating the source region and the base region to the drift layer, a gate insulating layer disposed on a surface of the trench, a gate electrode disposed on a surface of the gate insulating layer, a first electrode electrically coupled with the source region and the base region, a second electrode disposed on the second surface of the substrate, and a second conductivity-type layer disposed at a portion of the base region located under the source region. The second conductivity-type layer has the second conductivity type and has an impurity concentration higher than the base region. | 11-26-2009 |
20090311839 | Method for manufacturing silicon carbide semicondutor device having trench gate structure - A manufacturing method of a SiC device includes: forming a drift layer on a substrate having an orientation tilted from a predetermined orientation with an offset angle; obliquely implanting a second type impurity with a mask on the drift layer so that a deep layer is formed in the drift layer, wherein the impurity is implanted to cancel the offset angle; forming a base region on the deep layer and the drift layer; implanting a first type impurity on the base region so that a high impurity source region is formed; forming a trench having a bottom shallower than the deep layer on the source region to reach the drift layer; forming a gate electrode in the trench via a gate insulation film; forming a source electrode on the source region and the base region; and forming a drain electrode on the substrate. | 12-17-2009 |
20100006861 | Silicon carbide semiconductor device and manufacturing method of the same - A SiC semiconductor device includes: a substrate; a drift layer on a first side of the substrate; a trench in the drift layer; a base region contacting a sidewall of the trench; a source region in an upper portion of the base region; a gate electrode in the trench via a gate insulation film; a source electrode on the source region; and a drain electrode on a second side of the substrate. The source region has multi-layered structure including a first layer and a second layer. The first layer as an upper layer contacts the source electrode with ohmic contact. The second layer as a lower layer has an impurity concentration, which is lower than an impurity concentration of the first layer. | 01-14-2010 |
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 |
20100200866 | SiC single crystal substrate, SiC single crystal epitaxial wafer, and SiC semiconductor device - A direction of a dislocation line of a threading dislocation is aligned, and an angle between the direction of the dislocation line of the threading dislocation and a [0001]-orientation c-axis is equal to or smaller than 22.5 degrees. The threading dislocation having the dislocation line along with the [0001]-orientation c-axis is perpendicular to a direction of a dislocation line of a basal plane dislocation. Accordingly, the dislocation does not provide an extended dislocation on the c-face, so that a stacking fault is not generated. Thus, when an electric device is formed in a SiC single crystal substrate having the direction of the dislocation line of the threading dislocation, which is the [0001]-orientation c-axis, a SiC semiconductor device is obtained such that device characteristics are excellent without deterioration, and a manufacturing yield ration is improved. | 08-12-2010 |
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 |
20110017253 | Thermionic converter - A thermionic converter includes an emitter electrode and a collector electrode. The emitter electrode includes a P-type diamond semiconductor layer doped with a P-type impurity. The emitter electrode is configured to emit a thermion from the P-type diamond semiconductor layer when heat is applied from an external power source. The collector electrode includes an N-type diamond semiconductor layer doped with an N-type impurity. The N-type diamond semiconductor layer opposes the P-type diamond semiconductor layer and is located at a predetermined distance from the P-type diamond semiconductor layer. The collector electrode is configured to receive the thermion emitted from the emitter electrode at the N-type diamond semiconductor layer. | 01-27-2011 |
20110139205 | THERMIONIC CONVERTER - A thermionic converter for converting thermal energy to electrical energy includes an emitter and a collector. The emitter emits thermionic electrons upon receipt of heat from a heat source. The emitter is made of a first semiconductor material to which a first semiconductor impurity is doped with a first concentration. The collector is spaced and opposite to the emitter to receive the thermionic electrons emitted from the emitter so that the thermal energy is converted to electrical energy. The collector is made of a second semiconductor material to which a second semiconductor impurity is doped with a second concentration less than the first concentration. | 06-16-2011 |