Abstract: A semiconductor device includes a semiconductor substrate having an element region and a peripheral region. The semiconductor substrate includes a high-concentration layer, a drift layer, and a low-concentration layer. The high-concentration layer extends from the element region to the peripheral region, and is in contact with a lower electrode. The high-concentration layer has a thin plate portion and a thick plate portion. The drift layer is in contact with the upper surface of the thick plate portion. The low-concentration layer extends from the element region to the peripheral region, and is in contact with an upper surface of the thin plate portion and a side surface of a stepped portion at a boundary between the thin plate portion and the thick plate portion. A half or more of a quadrilateral region in a cross section of the semiconductor substrate is not depleted.

Abstract: In a guard ring section of a silicon carbide semiconductor device, an electric field relaxation layer for relaxing an electric field is formed in a surface layer portion of a drift layer, so that electric field is restricted from penetrating between guard rings. Thus, an electric field concentration is relaxed. Accordingly, a SiC semiconductor device having a required withstand voltage is obtained.

Abstract: A wafer processing apparatus is configured to process a wafer by supplying mist to a surface of the wafer. The wafer processing apparatus includes a furnace in which the wafer is disposed, a gas supplying device configured to supply gas into the furnace, a mist supplying device configured to supply the mist into the furnace, and a controller. The controller is configured to execute a processing step by controlling the gas supplying device and the mist supplying device to supply the gas and the mist into the furnace, respectively. The controller is further configured to control the mist supplying device to stop supplying the mist into the furnace while controlling the gas supplying device to keep supplying the gas into the furnace when the processing step ends.

Abstract: A semiconductor device includes a semiconductor substrate having a rectangular shape with a side extending in a first direction and another side extending in a second direction. A thermal conductivity in the first direction of the semiconductor substrate is different from a thermal conductivity in the second direction of the semiconductor substrate. The semiconductor substrate is configured to satisfy a mathematical relation of L1/L2=(K1/K2)0.5 with an inclusive tolerance range of ?5% to +5%, where L1 denotes a length of the semiconductor substrate in the first direction, L2 denotes a length of the semiconductor substrate in the second direction, K1 denotes the thermal conductivity in the first direction of the semiconductor substrate, and K2 denotes the thermal conductivity in the second direction of the semiconductor substrate.

Abstract: A film formation apparatus includes a stage for having a substrate thereon; a mist generation source that generates a mist of a solution containing at least water and in which a material for forming a film on the substrate is dissolved; a supply path that conveys the mist toward the substrate on the stage by a flow of a carrier gas; and a heater that heats at least a part of the supply path. The part of the supply path heated by the heater is provided as a mist heating section in which infrared rays are radiated from an inner surface of the supply path toward the mist. The inner surface of the supply path in the mist heating section is coated with a coating layer containing at least one of an oxide and a hydroxide of an element present in the mist.

Abstract: A film formation apparatus includes a stage, a heater, a mist supply source, a superheated vapor supply source, and a delivery device. The stage is configured to allow a substrate to be mounted thereon. The heater is configured to heat the substrate. The mist supply source is configured to supply mist of a solution that comprises solvent and a film material dissolved in the solvent. The superheated vapor supply source is configured to supply a superheated vapor of a same material as the solvent. The delivery device is configured to deliver the mist and the superheated vapor toward a surface of the substrate to grow a film containing the film material on the surface of the substrate.

Abstract: A mist generator may include a reservoir storing a solution, a plurality of ultrasonic vibrators, a mist delivery path, and a mist collector. The plurality of ultrasonic vibrators may be disposed under the reservoir and configured to apply ultrasonic vibration to the solution stored in the reservoir to generate mist of the solution in the reservoir. The mist delivery path may be configured to deliver the mist from an inside of the reservoir to an outside of the reservoir. The mist collector may be disposed above the solution in the reservoir, wherein an upper end of the mist collector may be connected to an upstream end of the mist delivery path, a lower end of the mist collector may include an opening, and a width of the mist collector may increase from the upper end toward the opening. The plurality of ultrasonic vibrators may be located directly under the opening.

Abstract: A method of forming a gallium oxide film is provided, and the method may include supplying mist of a material solution comprising gallium atoms and chlorine atoms to a surface of a substrate while heating the substrate so as to form the gallium oxide film on the surface of the substrate, in which a molar concentration of chlorine in the material solution is equal to or more than 3.0 times and equal to or less than 4.5 times a molar concentration of gallium in the material solution.

Abstract: A method of growing semiconductor layers may include: growing a first semiconductor layer on a surface of a substrate at which a crystal layer is exposed, wherein the first semiconductor layer is different from the crystal layer in at least one of a material and a crystal structure; cutting the first semiconductor layer such that a cut surface of the first semiconductor layer extends from a front surface of the first semiconductor layer to a rear surface of the first semiconductor layer; and growing a second semiconductor layer on the cut surface of the first semiconductor layer, wherein the second semiconductor layer has a material and a crystal structure that are same as those of the first semiconductor layer.

Abstract: A semiconductor device may include: a gallium oxide substrate including a first side surface constituted of a (100) plane, a second side surface constituted of a plane other than the (100) plane, and an upper surface; and an electrode in contact with the upper surface, in which the gallium oxide substrate may include: a diode interface constituted of a pn interface or a Schottky interface; and an n-type drift region connected to the electrode via the diode interface, and a shortest distance between the first side surface and the diode interface is shorter than a shortest distance between the second side surface and the diode interface.

Abstract: A method for manufacturing a semiconductor device includes: preparing a substrate made of a compound semiconductor containing a first element and a second element that is bonded to the first element and has an electronegativity smaller than that of the first element by 1.5 or more; causing an electric current to flow in the substrate; and dividing the substrate at a position including a current region where the electric current is caused to flow and along a cleavage plane of the substrate. A method for manufacturing a semiconductor device includes: stacking a first substrate and a second substrate each made of the compound semiconductor; and bonding the first substrate and the second substrate by causing an electric current to flow between the first substrate and the second substrate.

Abstract: A semiconductor device includes a semiconductor substrate comprising an upper surface and a lower surface, an upper electrode provided on the upper surface, and a lower electrode provided on the lower surface. The semiconductor substrate includes, in a planar view, a first section including a center of the semiconductor substrate and a second section located between the first section and a peripheral edge of the semiconductor substrate. The first and second sections each comprise a MOSFET structure including a body diode. The MOSFET structure in the first section and the MOSFET structure in the second section are different from each other such that a forward voltage drop of the body diode in the first section with respect to a current density is higher than a forward voltage drop of the body diode in the second section with respect to the current density.

Abstract: A method for producing a product including an oxide film of a second metal that is doped with a first metal includes generating a mist from a raw material solution in which both the first metal and the second metal are dissolved, and supplying the mist to a surface of a substrate to form the oxide film on the surface of the substrate. A pH of the raw material solution is less than 7.

Abstract: A method of forming an oxide film is provided. The method may include: supplying mist of a solution including a material of the oxide film dissolved therein to a surface of a substrate while heating the substrate at a first temperature so as to epitaxially grow the oxide film on the surface; and bringing the oxide film into contact with a fluid comprising oxygen atoms while heating the oxide film at a second temperature higher than the first temperature after the epitaxial growth of the oxide film.

Abstract: A method of forming an oxide film is provided. The method may include: supplying mist of a solution including a material of the oxide film dissolved therein to a surface of a substrate together with a carrier gas having an oxygen concentration equal to or less than 21 vol % so as to epitaxially grow the oxide film on the surface of the substrate; and bringing the oxide film into contact with a fluid comprising oxygen atoms after the epitaxial growth of the oxide film.

Abstract: A wafer processing apparatus is configured to process a wafer by supplying mist to a surface of the wafer. The wafer processing apparatus includes a furnace in which the wafer is disposed, a gas supplying device configured to supply gas into the furnace, a mist supplying device configured to supply the mist into the furnace, and a controller. The controller is configured to execute a processing step by controlling the gas supplying device and the mist supplying device to supply the gas and the mist into the furnace, respectively. The controller is further configured to control the mist supplying device to stop supplying the mist into the furnace while controlling the gas supplying device to keep supplying the gas into the furnace when the processing step ends.

Abstract: A method for forming a semi-conductive or conductive oxide film is provided. The oxide film is doped with a bismuth and made of an indium oxide, an aluminum oxide, a gallium oxide, an oxide including the gallium oxide, or an oxide of a combination thereof. The method includes supplying a mist of a solution to a surface of the substrate while heating the substrate. An oxide film material and a bismuth compound being dissolved in the solution. The bismuth compound is selected from the group consisting of bismuth ethoxide, bismuth acetate oxide, bismuth acetate, bismuth nitrate pentahydrate, bismuth nitrate, bismuth oxynitrate, bismuth 2-ethylhexanoate, bismuth octanoate, bismuth naphthenate, bismuth subgallate, bismuth subsalicylate, bismuth chloride, bismuth oxychloride, bismuth citrate, bismuth oxyacetate, bismuth oxide perchlorate, bismuth oxysalicylate, bismuth bromide, bismuth iodide, bismuth hydroxide, bismuth oxycarbonate, bismuth sulfide, bismuth sulfate, bismuth carbonate, and bismuth oxide.

Abstract: A film formation apparatus is configured to epitaxially grow a film on a surface of a substrate, and the film formation apparatus may include: a stage configured to allow the substrate to be mounted thereon; a heater configured to heat the substrate; a mist supply source configured to supply mist of a solution that comprises a solvent and a material of the film dissolved in the solvent; a heated-gas supply source configured to supply heated gas that comprises gas constituted of a same material as a material of the solvent and has a higher temperature than the mist; and a delivery device configured to deliver the mist and the heated gas to the surface of the substrate.

Abstract: A film formation apparatus is configured to supply mist of a solution to a surface of a substrate so as to epitaxially grow a film on the surface of the substrate. The film formation apparatus may be provided with: a furnace configured to house and heat the substrate; a reservoir configured to store the solution; a heater configured to heat the solution in the reservoir; an ultrasonic transducer configured to apply ultrasound to the solution in the reservoir so as to generate the mist of the solution in the reservoir; and a mist supply path configured to carry the mist from the reservoir to the furnace.

Abstract: In a guard ring section of a silicon carbide semiconductor device, an electric field relaxation layer for relaxing an electric field is formed in a surface layer portion of a drift layer, so that electric field is restricted from penetrating between guard rings. Thus, an electric field concentration is relaxed. Accordingly, a SiC semiconductor device having a required withstand voltage is obtained.