A semiconductor device for driving a load includes: a protection circuit configured to be connected to the load, the protection circuit including a protection diode, a diode-connected unipolar protection element, and a diode-connected bipolar protection element, all of which are connected in parallel so that when connected to the load, the protection diode, the diode-connected unipolar protection element, and the diode-connected bipolar protection element are connected in parallel to the load; and a switching circuit that is connected in series to the protection circuit and that performs a switching operation so as to drive the load. The protection diode, the diode-connected unipolar protection element, and the diode-connected bipolar protection element are connected in such a polarity that each is reverse-biased when the switching circuit is turned ON, and consume a discharge current resulting from a counter-electromotive force from the load when the switching circuit is turned OFF.

A semiconductor device includes a silicon carbide layer having first and second surfaces, a first insulating film on the first surface, a first electrode on the first insulating film, a first silicon carbide region of a first conductivity type in the silicon carbide layer, a second silicon carbide region of a second conductivity type in the first silicon carbide region, a third silicon carbide region of the first conductivity type in the second silicon carbide region, a second electrode on the second surface, which contains metal, silicon, and carbon, and a third electrode in contact with the third silicon carbide region, which contains metal, silicon, and carbon, and has a carbon concentration higher than a carbon concentration of the second electrode.

A device includes a vertical semiconductor switch including (i) a gate terminal and a first terminal provided on a substrate and (ii) a second terminal provided on the substrate, where the vertical semiconductor switch is configured to electrically connect or disconnect the first terminal and the second terminal, a first insulative film provided on the substrate, a second insulative film provided on the substrate, where the second insulative film is in contact with the first insulative film and thinner than the first insulative film, and a zener diode formed on the first insulative film and the second insulative film, where the zener diode includes a first portion that is formed on the first insulative film and connected to the first surface of the substrate and a second portion that is formed on the second insulative film and connected to the gate terminal.

A semiconductor device according to an embodiment includes a conductive region including titanium (Ti), oxygen (O), at least one first element from zirconium (Zr) and hafnium (Hf), and at least one second element from vanadium (V), niobium (Nb), and tantalum (Ta), an n-type first SiC region, a p-type second SiC region provided between the conductive region and the n-type first SiC region, a gate electrode, and a gate insulating layer provided between the conductive region, the p-type second SiC region, the n-type first SiC region, and the gate electrode.

A diffusion diode including a p.sup.+ diffusion region, a p-type diffusion region, and an n.sup.+ diffusion region is formed in the front surface of a semiconductor substrate. A polysilicon diode including a p.sup.+ layer and an n.sup.+ layer is formed on top of a local insulating film formed on the front surface of the semiconductor substrate and faces the diffusion diode in the depth direction. The diffusion diode and the polysilicon diode are reverse-connected by electrically connecting the n.sup.+ diffusion region to the n.sup.+ layer, thereby forming a lateral protection device. The p.sup.+ layer and p.sup.+ diffusion region are respectively electrically connected to a high voltage first terminal and a low voltage second terminal of the lateral protection device. The polysilicon diode blocks a forward current generated in the diffusion diode when the electric potential of the first terminal becomes lower than the electric potential of the second terminal.

A semiconductor device according to embodiments includes a p-type SiC region, a gate insulating film disposed on the p-type SiC region, and a gate electrode disposed on the gate insulating film and including a p-type impurity and 3C-SiC.

Provided is a semiconductor device according to an embodiment including: a first electrode; a second electrode; a third electrode provided between the first electrode and the second electrode; a first insulating film provided between the third electrode and the second electrode; a silicon carbide layer provided between the first insulating film and the second electrode; a first silicon carbide region provided between the third electrode and the second electrode, the first silicon carbide region being provided in the silicon carbide layer; a second silicon carbide region provided between the third electrode and the first silicon carbide region, the second silicon carbide region being provided in the silicon carbide layer; a third silicon carbide region provided between the third electrode and the second silicon carbide region, the third. silicon carbide region being provided in the silicon carbide layer; a fourth silicon carbide region provided between the third silicon carbide region and the second silicon carbide region, the fourth silicon carbide region being provided in the silicon carbide layer; and a fourth electrode provided between the first electrode and the fourth silicon carbide region, the fourth electrode being provided laterally adjacent to the third silicon carbide region, the fourth electrode containing a metal silicide, a first distance between the first electrode and a first interface between the fourth electrode and the fourth silicon carbide region being longer than a second distance between the first electrode and a second interface between the third silicon carbide region and the fourth silicon carbide region, and a third distance between a third interface between the fourth electrode and the first electrode and a fourth interface between the third silicon carbide region and the fourth silicon carbide region being shorter than a fourth distance between the fourth interface and a fifth interface between the third silicon carbide region and the first electrode.

An n.sup. drift region is disposed on the front surface of an n.sup.+ semiconductor substrate composed of a wide band gap semiconductor. A p-channel region is selectively disposed on the surface layer of the n.sup. drift region. A high-concentration p.sup.+ base region is disposed so as to adjoin the lower portion of the p-channel region inside the n.sup. drift region. Inside the high-concentration p.sup.+ base region, an n.sup.+ high-concentration region is selectively disposed at the n.sup.+ semiconductor substrate side. The n.sup.+ high-concentration region has a stripe-shaped planar layout extending to the direction that the high-concentration p.sup.+ base regions line up. The n.sup.+ high-concentration region adjoins a JFET region at one end portion in longitudinal direction of the stripe. Further, the n.sup.+ semiconductor substrate side of the n.sup.+ high-concentration region adjoins the part sandwiched between the high-concentration p.sup.+ base region and the n.sup.+ semiconductor substrate in the n.sup. drift region.

In one general aspect, a power device can include an active region having a plurality of pillars of a first conductivity type alternately arranged with a plurality of pillars of a second conductivity type. The power device can include a termination region surrounding at least a portion of the active region and can have a plurality of pillars of the first conductivity type alternately arranged with a plurality of pillars of the second conductivity type. Each of the plurality of pillars of the first conductivity type in the active region and the termination region can be defined by a trench. The power device can include an enrichment region at a bottom portion of one of the plurality of pillars of the first conductivity type in the active region.

An insulated gate bipolar translator (IGBT) with a built-in diode and a manufacturing method thereof are provided. The IGBT comprises: a semiconductor substrate (1) of the first conduction type which has a first major surface (1S1) and a second major surface (1S2), wherein the semiconductor substrate (1) comprises an active region (100) and a terminal protection area (200) which is located at the outer side of the active region; an insulated gate transistor unit which is formed at the side of the first major surface (1S1) of the active region (100), wherein a channel of the first conduction type is formed thereon during the conduction thereof; and first semiconductor layers (10) of the first conduction type and second semiconductor layers (11) of the second conduction type of the active region, which are formed at the side of the second major surface (1S2) of the semiconductor substrate (1) alternately, wherein the IGBT only comprises the second semiconductor layers (11) in the terminal protection area (200) which is located at the side of the second major surface (1S2) of the semiconductor substrate (1).