A nitride semiconductor device includes a transistor having a semiconductor stacked body formed on a substrate, and a pn light-emitting body formed on the semiconductor stacked body. The semiconductor stacked body includes a first nitride semiconductor layer, and a second nitride semiconductor layer formed on the first nitride semiconductor layer and having a bandgap wider than that of the first nitride semiconductor layer. The transistor includes: the semiconductor stacked body; a source electrode and a drain electrode formed away from each other on the semiconductor stacked body; and a gate electrode provided between the source electrode and the drain electrode and formed away from the source electrode and the drain electrode. The pn light-emitting body includes a p-type nitride semiconductor layer and an n-type nitride semiconductor layer to emit a light beam having an energy value higher than an electron trapping level existing in the semiconductor stacked body, in which the p-type nitride semiconductor layer of the pn light-emitting body is electrically connected to the gate electrode, and functions as a gate of the transistor.

A nitride semiconductor device includes: a substrate; a buffer layer formed on the substrate; a laminated body formed by two or more cycles of semiconductor layers each including a first nitride semiconductor layer, and a second nitride semiconductor layer having a larger band gap than a band gap of the first nitride semiconductor layer, the first and second nitride semiconductor layers being laminated in this order on the buffer layer; a first electrode; and a second electrode. A channel layer is formed in each of the semiconductor layers at an interface between the first nitride semiconductor layer and the second nitride semiconductor layer. A carrier concentration of the channel layer in the uppermost semiconductor layer is lower than a carrier concentration of each of the channel layers of the other semiconductor layers.

A semiconductor device includes a semiconductor layer including a Ga.sub.2O.sub.3-based single crystal, and an electrode that is in contact with a surface of the semiconductor layer. The semiconductor layer is in Schottky-contact with the electrode and has an electron carrier concentration based on reverse withstand voltage and electric field-breakdown strength of the Ga.sub.2O.sub.3-based single crystal.

A method for manufacturing a semiconductor device having an SiC-IGBT and an SiC-MOSFET in a single semiconductor chip, including forming a second conductive-type SiC base layer on a substrate, and selectively implanting first and second conductive-type impurities into surfaces of the substrate and base layer to form a collector region, a channel region in a surficial portion of the SiC base layer, and an emitter region in a surficial portion of the channel region, the emitter region serving also as a source region of the SiC-MOSFET.

In one aspect, a diode comprises: a semiconductor layer having a first side and a second side opposite the first side, the semiconductor layer having a thickness between the first side and the second side, the thickness of the semiconductor layer being based on a mean free path of a charge carrier emitted into the semiconductor layer; a first metal layer deposited on the first side of the semiconductor layer; and a second metal layer deposited on the second side of the semiconductor layer.

A Schottky barrier diode includes: an n+ type of silicon carbide substrate; an n type of epitaxial layer formed on a first surface of the n+ type of silicon carbide substrate; a plurality of p+ regions formed inside the n type of epitaxial layer; a Schottky electrode formed in an upper portion of the n type of epitaxial layer of an electrode region; and an ohmic electrode formed on a second surface of the n+ type of silicon carbide substrate, wherein the plurality of p+ regions are formed to be spaced apart from each other at a predetermined interval within the n type of epitaxial layer.

Disclosed is a method. The method includes forming a metal layer on a first surface of a semiconductor body; irradiating the metal layer with particles to move metal atoms from the metal layer into the semiconductor body and form a metal atom containing region in the semiconductor body; and annealing the semiconductor body. The annealing includes heating at least the metal atom containing region to a temperature of less than 500 C.

A semiconductor device according to the embodiments includes a SiC layer having a first plane, an insulating layer, and a region between the first plane and the insulating layer, the region including at least one element in the group consisting of Be (beryllium), Mg (magnesium), Ca (calcium), Sr (strontium), and Ba (barium), a full width at half maximum of a concentration peak of the element being equal to or less than 1 nm, and when a first area density being an area density of Si (silicon) and C (carbon) including a bond which does not bond with any of Si and C in the SiC layer at the first plane and a second area density being an area density of the element, the second area density being equal to or less than of the first area density.

A semiconductor device includes a trench formed in an epitaxial layer and an oxide layer that lines the sidewalls of the trench. The thickness of the oxide layer is non-uniform, so that the thickness of the oxide layer toward the top of the trench is thinner than it is toward the bottom of the trench. The epitaxial layer can have a non-uniform dopant concentration, where the dopant concentration varies according to the thickness of the oxide layer.

A silicon carbide semiconductor device includes an impurity region including a p type impurity and disposed within a silicon carbide layer to surround an element region as seen in plan view. The impurity region has a peak concentration of the p type impurity at a position within the silicon carbide layer distant from a first main surface. The peak concentration is not less than 110.sup.16 cm.sup.3 and not more than 510.sup.17 cm.sup.3. The impurity region is formed by implanting ions of the p type impurity into the silicon carbide layer. Then, a silicon dioxide film is formed to cover the first main surface of the silicon carbide layer by performing a thermal oxidation process on the silicon carbide layer, and the concentration of the p type impurity in the vicinity of the first main surface is lowered.