A silicon carbide semiconductor device includes a transistor region, a diode region, a gate line region, and a gate pad region. The gate pad region and the gate line region are each disposed to be sandwiched between the diode region and the diode region, and a gate electrode on the gate pad region and the gate line region is formed on an insulating film formed on an epitaxial layer. Thus, breakdown of the insulating film in the gate region can be prevented without causing deterioration in quality of the gate insulating film, upon switching and avalanche breakdown.

According to one embodiment, in a semiconductor device, The first semiconductor region is provided between the first and the second electrode. The second semiconductor region is provided between the first semiconductor region and the second electrode. The first and second connection region are electrically connected to the second electrode, reaches the first semiconductor region. The first insulating film is provided between the first connection region and the second semiconductor region and between the first connection region and the first semiconductor region. The second insulating film is provided between the second connection region and the second semiconductor region and between the second connection region and the first semiconductor region. The third connection region is provided between the first connection region and the second connection region, the third connection region is electrically connected to the second electrode, reaches the first semiconductor region or reaches the second semiconductor region.

A manufacturing method includes an implantation of impurities and laser irradiation. In the implantation, impurities are implanted to first and second areas so as to obtain a relationship that a total amount of the first impurities is larger than a total amount of the second impurities in a first depth range and a total amount of the second impurities is larger than a total amount of the first impurities in a second depth range (deeper range). In the irradiation, the first and second areas are irradiated with laser so that an energy density of the laser is larger on the second area than on the first area. A first conductivity type region is formed on the first area so as to be exposed on the surface, and a second conductivity type region is formed on the second area so as to be exposed on the surface.

A semiconductor device for restraining snapback is provided. The semiconductor device includes IGBT and diode regions. In a view of n-type impurity concentration distribution along a direction from a front surface to a rear surface, a local minimum value of an n-type impurity concentration is located at a border between cathode and buffer regions. A local maximum value of n-type impurity concentration is located in the buffer region. At least one of the butler and cathode regions includes a crystal defect region having crystal detects in a higher concentration than a region therearound. A peak of a crystal defect concentration in a view of crystal defect concentration distribution along the direction from the front surface to the rear surface is located in a region on the rear surface side with respect to a specific position having the n-type impurity concentration which is a half of the local maximum value.

Switching loss is reduced. A first surface of a semiconductor substrate has a portion included in an IGBT region and a portion included in a diode region. Trenches formed in the first surface include a gate trench and a boundary trench disposed between the gate trench and the diode region. A fourth layer of the semiconductor substrate is provided on the first surface and has a portion included in the diode region. The fourth layer includes a trench-covering well region that covers the deepest part of the boundary trench, a plurality of isolated well regions, and a diffusion region that connects the trench-covering well region and the isolated well regions. The diffusion region has a lower impurity concentration than that of the isolated well regions. A first electrode is in contact with the isolated well regions and away from the diffusion region.

An SiC semiconductor device includes an SiC semiconductor layer including an SiC monocrystal that is constituted of a hexagonal crystal and having a first main surface as a device surface facing a c-plane of the SiC monocrystal and has an off angle inclined with respect to the c-plane, a second main surface at a side opposite to the first main surface, and a side surface facing an a-plane of the SiC monocrystal and has an angle less than the off angle with respect to a normal to the first main surface when the normal is 0.

A transient voltage suppressor is disclosed that includes an electrode, a substrate disposed on the electrode, the substrate having a first doping, an epitaxial layer disposed on the substrate, the epitaxial layer having a second doping that is different from the first doping, a channel formed in the epitaxial layer having a width W, a length L and a plurality of curved regions, the channel forming a plurality of adjacent sections, the channel having a third doping that is different from the first doping and the second doping and a metal layer formed on top of the channel and contained within the width W of the channel.

A wide-band-gap diode and manufacturing method thereof are provided. The method of manufacturing a wide-band-gap diode involves growing an N-type doped epitaxial layer on an N-doped substrate. P-type ions are implanted into the epitaxial layer to form an active area, a junction termination extension region, and an edge region. The active area exhibits an axially symmetric graticule pattern, with higher doping area density towards the center of the active area. The junction termination extension region surrounds the active area, and the edge region encircles both of the active area and the junction termination extension region to enhance the wide-band-gap diode's capability to withstand surge currents.

A semiconductor device includes a semiconductor substrate that includes an IGBT region. A first lifetime control layer extending along a planar direction of the semiconductor substrate is provided in a range in a drift region that is closer to the rear surface than an intermediate portion of the semiconductor substrate in a thickness direction. A crystal defect density in the first lifetime control layer is higher than any of a crystal defect density in a region adjacent to the first lifetime control layer on the rear surface side and a crystal defect density in a region adjacent to the first lifetime control layer on a front surface side. A crystal defect density in a region between the first lifetime control layer and the rear surface is lower than a crystal defect density in a region between the first lifetime control layer and the front surface.

A semiconductor device, including a semiconductor substrate, a plurality of trenches formed on a front surface of the semiconductor substrate, a plurality of gate electrodes formed in the trenches, a base region and an anode region formed between adjacent trenches respectively in first and second element regions of the semiconductor substrate, a plurality of emitter regions and contact regions selectively formed in the base region, an interlayer insulating film covering the gate electrodes, first and second contact holes penetrating the interlayer insulating film, a plurality of contact plugs embedded in the first contact holes, a first electrode contacting the contact plugs and contacting the anode region via the second contact hole, a collector region and a cathode region formed on a back surface of the semiconductor substrate respectively in the first and second element regions, and a second electrode contacting the collector region and the cathode region.