Provided is a semiconductor device in which a leakage current is reduced, the semiconductor device which is particularly useful for power devices. A semiconductor device including at least: an n+-type semiconductor layer, which contains a crystalline oxide semiconductor as a major component; an n−-type semiconductor layer that is placed on the n+-type semiconductor layer, the n−-type semiconductor layer containing a crystalline oxide semiconductor as a major component; a high-resistance layer with at least a part thereof being embedded in the n−-type semiconductor layer, the high-resistance layer having a bottom surface located at a distance of less than 1.5 μm from an upper surface of the n+-type semiconductor layer; and a Schottky electrode that forms a Schottky junction with the n−-type semiconductor layer, the Schottky electrode having an edge located on the high-resistance layer.

A semiconductor device and a method of manufacturing a semiconductor are provided. In an embodiment, a first trench is formed in a silicon carbide layer. A second trench is formed in the silicon carbide layer to define a mesa in the silicon carbide layer between the first trench and the second trench. A first doped semiconductor material is formed in the first trench and a second doped semiconductor material is formed in the second trench. A third doped semiconductor material is formed over the mesa to define a heterojunction at an interface between the third doped semiconductor material and the mesa.

A manufacturing method of an electronic device includes: forming a drift layer of an N type; forming a trench in the drift layer; forming an edge-termination structure alongside the trench by implanting dopant species of a P type; and forming a depression region between the trench and the edge-termination structure by digging the drift layer. The steps of forming the depression region and the trench are carried out at the same time. The step of forming the depression region comprises patterning the drift layer to form a structural connection with the edge-termination structure having a first slope, and the step of forming the trench comprises etching the drift layer to define side walls of the trench, which have a second slope steeper than the first slope.

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 method for manufacturing a semiconductor element includes preparing a semiconductor wafer that includes a substrate including a Ga.sub.2O.sub.3-based semiconductor and an epitaxial layer including a Ga.sub.2O.sub.3-based semiconductor and located on the substrate, fixing the epitaxial layer side of the semiconductor wafer to a support substrate, thinning the substrate of the semiconductor wafer fixed to the support substrate, after the thinning of the substrate, forming an electrode on a lower surface of the substrate, bonding or forming a support metal layer on a lower surface of the electrode of the semiconductor wafer, and dicing the semiconductor wafer into individual pieces, thereby obtaining plural semiconductor elements each including the support metal layer. Thermal conductivity of the support metal layer is higher than thermal conductivity of the substrate.

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.

The present invention relates to a Semiconductor device including a first electrode, a second electrode and at least one semiconductor material or layer between the first and second electrode. The semiconductor device further includes at least one field plate structure for increasing a breakdown voltage of the semiconductor device. The at least one field plate structure comprises at least two recesses in the at least one semiconductor material or layer, the at least two recesses defining a semiconductor region therebetween, and a third electrode contacting or provided on the semiconductor region.

A semiconductor device includes a semiconductor part of a first conductivity type, a trench being provided in the semiconductor part at a front surface side; a first electrode provided on a back surface of the semiconductor part; a second electrode provided on the front surface of the semiconductor part; a first semiconductor layer of a second conductivity type provided inside the trench; and a insulating film electrically isolating the first semiconductor layer from the semiconductor part. The second electrode is electrically connected to the semiconductor part and the first semiconductor layer. The second electrode contacts the semiconductor part with a rectification property.

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 semiconductor device of the present invention includes a first conductivity type semiconductor layer made of a wide bandgap semiconductor and a Schottky electrode formed to come into contact with a surface of the semiconductor layer, and has a threshold voltage V.sub.th of 0.3 V to 0.7 V and a leakage current J.sub.r of 1×10.sup.−9 A/cm.sup.2 to 1×10.sup.−4 A/cm.sup.2 in a rated voltage V.sub.R.