A silicon carbide semiconductor device includes an n-type silicon carbide semiconductor substrate, a drain electrode electrically connected to a rear face, an n-type semiconductor layer having a second impurity concentration lower than the first impurity concentration, a p-type first semiconductor region, an n-type second semiconductor region, and an n-type third semiconductor region. A trench is formed having a gate electrode therein in which the bottom face of the trench contacts the p-type semiconductor region. A metal layer is electrically connected to the third semiconductor region, and a source electrode electrically connects the second semiconductor region and the metal layer to each other.

A semiconductor device includes an n-doped monocrystalline semiconductor substrate having a substrate surface, an amorphous n-doped semiconductor surface layer at the substrate surface of the n-doped monocrystalline semiconductor substrate, and a Schottky-junction forming material in contact with the amorphous n-doped semiconductor surface layer. The Schottky-junction forming material forms at least one Schottky contact with the amorphous n-doped semiconductor surface layer.

Systems, methods, and other embodiments associated with gas detecting sensors. According to one embodiment, a gas sensor includes a metal layer, a barrier interlayer, a substrate layer, a first insulating layer, a conduction path, a contact pad, and a second insulating layer. The conduction path connects the metal layer to the contact pad. The second insulating layer prevents diffusion through the contact pad, the conduction path, or the metal layer. The sensor includes a wire bonded electrical connection to the contact pad such that voltage can be determined and/or applied.

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.

A method of manufacturing a semiconductor apparatus includes preparing a semiconductor substrate, and forming a Schottky electrode that is in Schottky contact with a surface of the semiconductor substrate. The Schottky electrode is made of a metal material containing a predetermined concentration of oxygen atoms.

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 includes a first semiconductor layer of a first conductivity type provided on a front surface of a silicon carbide semiconductor substrate of the first conductivity type, a first semiconductor region of a second conductivity type, a second semiconductor region of the second conductivity type and connected to the first semiconductor region, a first electrode forming a Schottky-contact with the first semiconductor layer and the first semiconductor region, and a second electrode forming an ohmic contact with the second semiconductor region. The second electrode has a TiAl alloy layer on a surface in contact with the first electrode. The second electrode further has therein a nickel silicide layer containing titanium.

A semiconductor device according to the present invention includes a first conductive-type SiC semiconductor layer, and a Schottky metal, comprising molybdenum and having a thickness of 10 nm to 150 nm, that contacts the surface of the SiC semiconductor layer. The junction of the SiC semiconductor layer to the Schottky metal has a planar structure, or a structure with recesses and protrusions of equal to or less than 5 nm.

A method for manufacturing a SiC mixed trench Schottky diode may include steps of providing a substrate and an epitaxial layer on top of the substrate; forming a plurality of trenches on a surface of the epitaxial layer; conducting ion implantation at a bottom portion of each trench; conducting ion implantation at sidewalls of each trench; forming an ohmic contact metal at a bottom portion of the Schottky diode; forming a Schottky contact metal on top of the epitaxial layer and in the trenches. In one embodiment, the substrate is an N.sup.+ type SiC and the epitaxial layer is an N.sup. type SiC. In another embodiment, the step of forming a plurality of trenches on a surface of the epitaxial layer may include the step of etching the surface of the epitaxial layer by either dry etching or wet etching.

A silicon carbide semiconductor device has an active region, a first-conductivity-type region, and an edge termination region. The active region has first second-conductivity-type regions, a silicide film, and a first electrode; the edge termination region has a second second-conductivity-type region. The active region is configured by an ohmic region in which the silicide film is in contact with the first second-conductivity-type region, non-operating regions in which the first electrode is in contact with the first second-conductivity-type regions, and a Schottky region in which the first electrode is in contact with the first-conductivity-type region. The ohmic region, the non-operating regions, and the Schottky regions are provided in a striped pattern. A bottom surface of the silicide film in the ohmic region is positioned deeper than is an interface between the first electrode and the first second-conductivity-type regions in each of the plurality of non-operating regions.