A lateral insulated gate bipolar transistor (IGBT) with a low turn-on overshoot current is provided to reduce a peak value of a current flowing through a device during turn-on of a second gate pulse while preventing a current capability and a withstand voltage capability from being degraded. The lateral IGBT includes: a buried oxygen arranged on a P-type substrate, an N-type drift region arranged on the buried oxygen, on which a P-type body region and an N-type buffer region are arranged, a P-type collector region arranged in the N-type buffer region, a field oxide layer arranged above the N-type drift region, a P-type well region arranged in the P-type body region, and a P-type emitter region and an emitter region arranged in the P-type well region, where inner boundaries of the foregoing 4 regions are synchronously recessed to form a pinch-off region. A gate oxide layer is arranged on a surface of the P-type body region, and a polysilicon gate is arranged on the gate oxide layer. The polysilicon gate includes a first gate located above the surface of the P-type body region and a second gate located above the pinch-off region and the N-type drift region. The first gate is connected to a first gate resistor, and the second gate is connected to a second gate resistor.

S1≤S2<S3 being satisfied, where S1 is a surface area of the first gate electrode and the third semiconductor layer facing each other via the first insulating film, S2 is a surface area of the second gate electrode and the third semiconductor layer facing each other via the second insulating film, and S3 is a surface area of the third gate electrode and the third semiconductor layer facing each other via the third insulating film.

To provide a semiconductor device having excellent conduction characteristics of a transistor portion and a diode portion. The semiconductor device having a transistor portion and a diode portion, the semiconductor device includes: a drift region of a first conductivity type provided on a semiconductor substrate, a first well region of a second conductivity type provided on an upper surface side of the semiconductor substrate, an anode region of the second conductivity provided on the upper surface side of the semiconductor substrate, in the diode portion, and a first high concentration region of a second conductivity type which is provided in contact with a first well region between the anode region and the first well region, and has a higher doping concentration than the anode region.

A silicon carbide semiconductor device includes a substrate, a drift layer disposed above the substrate, a base region disposed above the drift layer, a source region disposed above the base region, a gate trench formed deeper than the base region from a surface of the source region, a gate insulating film covering an inner wall surface of the gate trench, a gate electrode disposed on the gate insulating film, an interlayer insulating film covering the gate electrode and the gate insulating film and having a contact hole, a source electrode brought in ohmic contact with the source region through the contact hole, and a drain electrode disposed to a rear surface of the substrate. The source region has a lower impurity concentration on a side close to the base region than on a surface side brought in ohmic contact with the source region.

Provided is a semiconductor device having a transistor portion and a diode portion, including: a drift region of a first conductivity type provided in a semiconductor substrate; an accumulation region of a first conductivity type provided on a front surface side of the semiconductor substrate with respect to the drift region in the transistor portion and the diode portion; and a first lifetime control region provided on the front surface side of the semiconductor substrate in the transistor portion and the diode portion.

An IGBT chip having a mixed gate structure includes a plurality of mixed gate units. Each of the mixed gate units includes a source region (3) and a gate region. The gate region includes a planar gate region (1) and a trench gate region (2), which are respectively disposed at both sides of the source region (3). A planar gate and a trench gate are compositely disposed on the same cell (16), thereby greatly improving chip density while retaining both trench gate's features of low on-state energy loss and high current density and planar gate's feature of wide safe operating area.

A semiconductor device includes: a semiconductor substrate; a plurality of trenches provided on a top surface side of the semiconductor substrate; am insulated gate electrode structure buried inside the respective trenches; an interlayer insulating film deposited on top surfaces of the semiconductor substrate and the insulated gate electrode structure; and a silicide layer deposited at a bottom of a contact hole penetrating the interlayer insulating film so as to be in contact with the top surface of the semiconductor substrate interposed between the trenches adjacent to each other, wherein at least a part of a bottom surface of the silicide layer is located at a higher position than a bottom surface of the interlayer insulating film.

In one aspect, a method of fabricating a transistor includes implanting ions into a first portion of a second epitaxial layer to form a recombination region, depositing a second portion of the second epitaxial layer having an n-type dopant on the recombination region, and forming trenches in the second portion of the second epitaxial layer.

Provided is a semiconductor device in which one mesa portion of two mesa portions in contact with a gate trench portion is an active mesa portion in which an emitter region of a first conductivity type having a doping concentration higher than that of a drift region is arranged in contact with the gate trench portion, the other mesa portion of two mesa portions in contact with the gate trench portion is a dummy mesa portion having no emitter region, and a dummy contact resistance which is a resistance of the dummy mesa portion and an emitter electrode is 1000 times or more as high as an active contact resistance which is a resistance of the active mesa portion and the emitter electrode.

Provided is a semiconductor device having transistor and diode sections. The semiconductor device comprises: a gate metal layer provided above the upper surface of a semiconductor substrate; an emitter electrode provided above the upper surface of the semiconductor substrate; a first conductivity-type emitter region provided on the semiconductor substrate upper surface side in the transistor section; a gate trench section, which is provided on the semiconductor substrate upper surface side in the transistor section, is electrically connected to the gate metal layer, and is in contact with the emitter region; an emitter trench section, which is provided on the semiconductor substrate upper surface side in the diode section, and is electrically connected to the emitter electrode; and a dummy trench section, which is provided on the semiconductor substrate upper surface side, is electrically connected to the gate metal layer, and is not in contact with the emitter region.