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.

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.

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, 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.

A semiconductor Schottky rectifier built in an epitaxial semiconductor layer over a substrate has an anode structure and a cathode structure extending from the surface of the epitaxial layer. The cathode contact structure has a trench structure near the epi-layer and a vertical sidewall surface covered with a gate oxide layer. The cathode structure further comprises a polysilicon element adjacent to the gate oxide layer.

An SBD of a JBS structure has on a front side of a semiconductor substrate, nickel silicide films in ohmic contact with p-type regions and a FLR, and a titanium film forming a Schottky junction with an n.sup.−-type drift region. A thickness of each of the nickel silicide films is in a range from 300 nm to 700 nm. The nickel silicide films each has a first portion protruding from the front surface of the semiconductor substrate in a direction away from the front surface of the semiconductor substrate, and a second portion protruding in the semiconductor substrate from the front surface of the semiconductor substrate in a depth direction. A thickness of the first portion is equal to a thickness of the second portion. A width of the second portion is wider than a width of the first portion.

An SBD of a JBS structure has on a front side of a semiconductor substrate, nickel silicide films in ohmic contact with p-type regions and a FLR, and a titanium film forming a Schottky junction with an n.sup.−-type drift region. A thickness of each of the nickel silicide films is in a range from 300 nm to 700 nm. The nickel silicide films each has a first portion protruding from the front surface of the semiconductor substrate in a direction away from the front surface of the semiconductor substrate, and a second portion protruding in the semiconductor substrate from the front surface of the semiconductor substrate in a depth direction. A thickness of the first portion is equal to a thickness of the second portion. A width of the second portion is wider than a width of the first portion.

An insulated gate bipolar transistor includes a source electrode, a collector electrode, a source layer, a base layer, a drift layer and a collector layer. Trench gate electrodes extend through the base layer into the drift layer. A channel is located between the source layer, the base layer and the drift layer. A trench Schottky electrode is adjacent to one of the trench gate electrodes and includes an electrically conductive Schottky layer arranged lateral to the base layer and extends through the base layer into the drift layer. The Schottky layer is electrically connected to the source electrode. Collection areas are located in the drift layer at a respective trench gate electrode bottom of the trench gate electrodes or of the trench Schottky electrode. The Schottky layer forms a Schottky contact to the collection area at a contact area.

An insulated gate bipolar transistor includes a source electrode, a collector electrode, a source layer, a base layer, a drift layer and a collector layer. Trench gate electrodes extend through the base layer into the drift layer. A channel is located between the source layer, the base layer and the drift layer. A trench Schottky electrode is adjacent to one of the trench gate electrodes and includes an electrically conductive Schottky layer arranged lateral to the base layer and extends through the base layer into the drift layer. The Schottky layer is electrically connected to the source electrode. Collection areas are located in the drift layer at a respective trench gate electrode bottom of the trench gate electrodes or of the trench Schottky electrode. The Schottky layer forms a Schottky contact to the collection area at a contact area.

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.