In a general aspect, a silicon carbide (SiC) rectifier can include a substrate of a first conductivity type, a drift region of the first conductivity type, a junction field effect transistor (JFET) region of the first conductivity type, a body region of a second conductivity type, an anode implant region of the first conductivity type, and a channel of the first conductivity type. The channel can be in contact with and disposed between the JFET region and the anode implant region. A portion of the channel between the anode implant region and the JFET region can be disposed in the body region, The channel can be configured to be off under zero-bias conditions, and on at a positive turn-on voltage.

A semiconductor device may include: an n type of layer disposed on a first surface of a substrate; a p+ type of region disposed on the first surface of the substrate; a p type of region disposed at a top portion of the n type of layer; a first electrode disposed on the p+ type of region and the p type of region; and a second electrode disposed on a second surface of the substrate, wherein the side surface of the p+ type of region and the side surface of the n type of layer are in contact, and the thickness of the p+ type of region is the same as the thickness of the n type of layer and the thickness of the p type of region.

A method of manufacturing a silicon carbide semiconductor device includes forming a first silicon carbide layer of a first conductivity type on a front surface of a silicon carbide semiconductor substrate. A thermal oxidation film is formed on a surface of a base body including the first silicon carbide layer. The thermal oxidation film is subsequently removed using a solution containing hydrofluoric acid. The base body is washed with a mixture of ammonia water and a hydrogen peroxide solution, a mixture of hydrochloric acid and a hydrogen peroxide solution, and a dilute hydrofluoric acid. The base body is held at temperature of 700 degrees C. to 1700 degrees C., and an insulating film is deposited on the base body.

A semiconductor device is manufactured by implanting impurity ions in one surface of a semiconductor substrate made of silicon carbide; irradiating a region of the semiconductor substrate implanted with the impurity ions with laser light of a wavelength in the ultraviolet region; and forming, on a surface of a high-concentration impurity layer formed by irradiating with the laser light, an electrode made of metal in ohmic contact with the high-concentration impurity layer. When irradiating with the laser light, a first concentration peak of the impurity ions that exceeds a solubility limit concentration of the impurity ions in silicon carbide is formed in a surface region near the one surface of the semiconductor substrate within the high-concentration impurity layer.

A semiconductor device constituted of: a semiconductor layer; and a field layer patterned on said semiconductor layer, said field layer constituted of material having characteristics which block diffusion of mobile ions and maintain structural integrity at activation temperatures of up to 1200 degrees centigrade.

All of intervals between adjacent p type guard rings are set to be equal to or less than an interval between p type deep layers. As a result, the interval between the p type guard rings becomes large, i.e., the trenches are formed sparsely, so that the p type layer is prevented from being formed thick at the guard ring portion when the p type layer is epitaxially grown. Therefore, by removing the p type layer in the cell portion at the time of the etch back process, it is possible to remove the p type layer without leaving any residue in the guard ring portion. Therefore, when forming the p type deep layer, the p type guard ring and the p type connection layer by etching back the p type layer, the residue of the p type layer is restricted from remaining in the guard ring portion.

According to an embodiment, provided is a semiconductor device including: a first electrode; a second electrode; and a silicon carbide layer disposed between the first electrode and the second electrode, the silicon carbide layer including: a first silicon carbide region of an n-type; and a second silicon carbide region disposed between the first silicon carbide region and the first electrode, the second silicon carbide being in contact with the first electrode, and the second silicon carbide containing one oxygen atom bonding with four silicon atoms.

According to an embodiment, a semiconductor device includes a substrate, a first semiconductor region, a second semiconductor region, a third semiconductor region, fourth semiconductor regions, and a first electrode. The second semiconductor region is provided on the first semiconductor region. The second semiconductor region includes a first portion and a second portion connected to the first portion in a first direction parallel to the first surface of the substrate. A conductivity type of the second semiconductor region is a second conductivity type. The first electrode is provided on the first portion of the second semiconductor region, the third semiconductor region, and the fourth semiconductor regions and is in contact with the first portion of the second semiconductor region.

A p-type oxide semiconductor is prevented from being oxidized by oxygen in an n-type oxide semiconductor even if the p-type oxide semiconductor is provided as a termination structure in the n-type oxide semiconductor. A semiconductor device includes an n-type gallium oxide substrate, an anode electrode joined to the n-type gallium oxide substrate, and a cathode electrode provided on the n-type gallium oxide substrate. Current flows between the anode electrode and the cathode electrode via the n-type gallium oxide substrate provided between the anode electrode and the cathode electrode. The semiconductor device further includes a p-type oxide semiconductor layer provided adjacent to a junction between the anode electrode and the n-type gallium oxide substrate, and a nitride layer provided between the p-type oxide semiconductor layer and the n-type gallium oxide substrate.

A semiconductor device may include an n type of layer disposed at a first surface of a substrate; a p type of region and a p+ type of region disposed at a top portion of the n type of layer; a first electrode disposed on the p type of region and the p+ type of region; and a second electrode disposed at a second surface of the substrate, wherein the first electrode includes a first metal layer disposed on the p type of region and a second metal layer disposed on the first metal layer, and the first metal layer is in continuous contact with the p type of region.