Patent application number | Description | Published |
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 |
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 |
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 |
Patent application number | Description | Published |
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 |
20090160008 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A semiconductor device that includes an n-type semiconductor substrate and an upper electrode formed on an upper face of the semiconductor substrate and a method of manufacturing the semiconductor device are provided. A p-type semiconductor region is repeatedly formed in the semiconductor substrate in at least one direction parallel to the substrate plane so as to be exposed on an upper face of the semiconductor substrate. The upper electrode includes a metal electrode portion; and a semiconductor electrode portion made of a semiconductor material whose band gap is narrower than that of the semiconductor substrate. The semiconductor electrode portion is provided on each p-type semiconductor region exposed on the upper face of the semiconductor substrate. The metal electrode portion is in Schottky contact with an n-type semiconductor region exposed on the upper face of the semiconductor substrate, and is in ohmic contact with the semiconductor electrode portion. | 06-25-2009 |
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 |
20090269908 | Manufacturing method of a semiconductor device - A manufacturing method of a semiconductor device comprises a process of doping conductive impurities in a silicon carbide substrate, a process of forming a cap layer on a surface of the silicon carbide substrate, a process of activating the conductive impurities doped in the silicon carbide substrate, a process of oxidizing the cap layer after a first annealing process, and a process of removing the oxidized cap layer. It is preferred that the cap layer is formed from material that includes metal carbide. Since the oxidation onset temperature of metal carbide is comparatively low, the oxidization of the cap layer becomes easy if metal carbide is included in the cap layer. Specifically, it is preferred that the cap layer is formed from metal carbide that has an oxidation onset temperature of 1000 degrees Celsius or below, such as tantalum carbide. | 10-29-2009 |
20110151654 | SEMICONDUCTOR DEVICE MANUFACTURING METHOD - First, a first layer made of Ni or an alloy including Ni may be formed on an upper surface of a semiconductor layer. Next, a second layer made of silicon oxide may be formed on an upper surface of the first layer. Next, a part, which corresponds to a semiconductor region, of the second layer may be removed. Next, second conductive type ion impurities may be injected from upper sides of the first and second layers to the semiconductor layer after the removing step. | 06-23-2011 |
20110207321 | SEMICONDUCTOR DEVICE MANUFACTURIING METHOD - A method for manufacturing a semiconductor device including a semiconductor substrate composed of silicon carbide, an upper surface electrode which contacts an upper surface of the substrate, and a lower surface electrode which contacts a lower surface of the substrate, the method including steps of: (a) forming an upper surface structure on the upper surface side of the substrate, and (b) forming a lower surface structure on the lower surface side of the substrate. The step (a) comprises steps of: (a1) depositing an upper surface electrode material layer on the upper surface of the substrate, the upper surface electrode material layer being a raw material layer of the upper surface electrode, and (a2) annealing the upper surface electrode material layer. The step (b) comprises steps of: (b1) depositing a lower surface electrode material layer on the lower surface of the substrate, the lower surface electrode material layer being a raw material layer of the lower surface electrode, and (b2) annealing the lower surface electrode material layer with a laser to make an ohmic contact between the lower surface electrode and the substrate. | 08-25-2011 |