A semiconductor device includes: a semiconductor layer including a trench; an insulating film covering an inner surface of the trench; a conductor embedded in the trench covered with the insulating film; and a Schottky junction layer. A Schottky junction is formed by the Schottky junction layer and a region being part of a semiconductor layer surface and being adjacent to the trench. A surface of the conductor is located at an elevation lower than the surface of the semiconductor layer. The semiconductor layer surface includes a sloping portion adjacent to an inner wall surface of the trench. The sloping portion has a downward gradient that is steeper in a region closer to the inner wall surface.

A semiconductor device A1 includes: a semiconductor layer including a trench; an insulating film covering an inner surface of the trench; a conductor embedded in the trench covered with the insulating film; a silicide layer; and a metal layer. A Schottky junction is formed by the silicide layer and a region being part of a semiconductor layer surface and being adjacent to the trench. A region including an end face of the silicide layer and an upper end face of the insulating film is covered with the metal layer, with no gap between one part and another part of the metal layer on the region. The end face is located at elevations higher than the upper end face. The metal layer and the silicide layer contain the same kind of metallic element.

A semiconductor device includes a semiconductor part, first and second electrodes. The semiconductor part includes first to third layers. The first electrode is provided on a back surface of the semiconductor part. The second electrode is provided on a front surface of the semiconductor part. The first layer of a first conductivity type extends between the first and second electrodes. The second layer of a second conductivity type is provided between the first layer and the second electrode. The third layer of the second conductivity type is provided between the second layer and the second electrode. The second electrode includes a buried contact portion and a surface contact portion. The buried contact portion extends into the second layer from the front surface of the semiconductor part and contacts the second layer. The surface contact portion contacts the third layer at the front surface of the semiconductor part.

An electron extraction type free-wheeling diode device and a preparation method thereof are provided by the present disclosure, and more than one first structures for increasing the density of electron extraction pathways are provided on a N-type drift region. Each of the first structures includes a lightly doped P-type base region, a heavily doped N-type emitter region located on the lightly doped P-type base region, a P-type trench anode region, and a trench region located on the P-type trench anode region. The barrier height of the punch-through NPN triode can be tuned in a wide range, which has beneficial effects on soft and fast adjustment of the reverse recovery process.

An insulating film is formed on a front surface of a semiconductor layer in which a trench has been formed. An electric conductor is embedded into the trench, and the insulating film that has been formed on the semiconductor layer surface and that is adjacent to the trench is removed by etching so as to expose the semiconductor layer surface. The semiconductor layer surface is further etched such that the semiconductor layer surface is lowered relative to an upper end of the insulating film covering the inner surface of the trench. After that, a Schottky barrier junction is formed at the semiconductor layer surface.

A Schottky barrier diode includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and formed on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, a cathode electrode brought into ohmic contact with the semiconductor substrate, an insulating film covering the inner wall of a trench formed in the drift layer, and a protective film covering the anode electrode, wherein a part of the protective film is embedded in the trench. The part of the protective film is thus embedded in the trench, so that adhesion performance between the anode electrode and protective film is enhanced. This makes it possible to prevent peeling at the boundary between the anode electrode and the protective film.

A silicon substrate has first to fourth semiconductor regions. The third semiconductor region is separated from the first semiconductor region of a first conductivity type by the second semiconductor region of a second conductivity type. The fourth semiconductor region of the second conductivity type is separated from the second semiconductor region by the third semiconductor region. A first electrode is provided on a first surface. A barrier metal layer is provided on a first portion of a second surface. A second electrode is provided on the second surface, and is separated from the first portion of the second surface by the barrier metal layer. The second electrode includes an aluminum-silicon (AlSi) layer in contact with a second portion of the second surface, and an Al layer separated from the second portion of the second surface by the AlSi layer.

A method includes forming first and second trenches in a semiconductor substrate. The method further includes filling the first and second trenches with polysilicon. The polysilicon is oppositely doped from the semiconductor substrate. A Schottky contact is formed on the semiconductor substrate between the first and second trenches. The method also includes forming an anode for the Schottky contact. The anode is coupled to the polysilicon in the first and second trenches.

The disclosure provides a semiconductor package having an isolation structure comprising an isolation trench filled with dielectric material, where the isolation structure traverses the thickness of the isolated semiconductor dies.

A semiconductor device includes a lead frame including a raised portion on a surface, and a semiconductor element that is face-down mounted on the lead frame and includes a substrate including a Ga.sub.2O.sub.3-based semiconductor, an epitaxial layer including a Ga.sub.2O.sub.3-based semiconductor and stacked on the substrate, a first electrode connected to a surface of the substrate on an opposite side to the epitaxial layer, and a second electrode connected to a surface of the epitaxial layer on an opposite side to the substrate and including a field plate portion at an outer peripheral portion. The semiconductor element is fixed onto the raised portion. An outer peripheral portion of the epitaxial layer, which is located on the outer side of the field plate portion, is located directly above a flat portion of the lead frame that is a portion at which the raised portion is not provided.