A groove for air ventilation is formed in a rib with a substantially rectangular ring shape which is provided so as to surround a concave portion provided in a rear surface of a semiconductor chip. The groove is provided in each side or at each corner of the rib so as to traverse the rib from the inner circumference to the outer circumference of the rib. The depth of the groove is equal to or less than the depth of the concave portion provided in the rear surface of the chip. In this way, it is possible to reliably solder a semiconductor device, in which the concave portion is provided in the rear surface of the semiconductor chip and the rib is provided in the outer circumference of the concave portion, to a base substrate, without generating a void in a drain electrode provided in the concave portion.

A power semiconductor device includes a semiconductor substrate layer of a first conductive type which has a lower part semiconductor layer of a second conductive type and an active region that includes a body region of the second conductive type, a source region of the first conductive type disposed in the body region, and a first doped region of the first conductive type at least a part of which is disposed below the body region. An emitter electrode is electrically connected to the source region, and a groove extends into the substrate layer and includes a shielding electrode electrically connected to the emitter electrode. The groove extends to a deeper depth into the substrate layer than the first doped region. At least a part of a gate is formed above at least a part of the source region and the body region, and is electrically insulated from the shielding electrode.

A semiconductor device includes a drift region of a first conductivity type, a channel forming region of a second conductivity type that is selectively provided in a first main surface of the drift region, a first main electrode region of the first conductivity type that is selectively provided in an upper part of the channel forming region, a second main electrode region of the second conductivity type that is provided in a second main surface of the drift region, and a high-concentration region of the first conductivity type that is provided in a portion of the drift region below the channel forming region so as to be separated from the channel forming region. The high-concentration region has a higher impurity concentration than the drift region and the total amount of first-conductivity-type impurities in the high-concentration region is equal to or less than 2.010.sup.12 cm.sup.2.

In a general aspect, a power semiconductor device can include a collector region disposed on a substrate, the collector region can include n-type silicon carbide (SiC). The power semiconductor device can also include a base region disposed on the collector region. The base region can include p-type SiC doped with gallium. The power semiconductor device can include an emitter region disposed on the base region. The emitter region can include n-type SiC carbide.

An SJ-MOSFET and IGBT are provided in a single semiconductor chip. Furthermore, a balance is made between a carrier amount of n-type columns and a carrier amount of p-type columns, to encourage formation of a depletion layer in when a reverse voltage is applied in the SJ-MOSFET section. Provided is a includes a semiconductor substrate, a super junction structure formed on a front surface side of the semiconductor substrate, and a field stop layer formed at a position overlapping with the super junction structure on a back surface side of the semiconductor substrate, in a manner to not contact an end of the super junction structure on the back surface side.

A semiconductor device includes a drift layer of a first conductivity-type, having a superjunction structure, including a plurality of columns of a second conductivity-type, a plane pattern of each of the columns extends along a parallel direction to the principal surface of the layer, the columns are arranged at regular intervals; a plurality of well regions of the second conductivity-type provided in a surface-side layer of the layer of the first conductivity-type; a plurality of source regions of the first conductivity-type selectively provided in the plurality of well regions; a gate insulating film provided on the principal surface; an array of gate electrodes disposed on the gate insulating film, each of the gate electrodes is provided so as to bridge the corresponding source regions in a pair of neighboring two well regions; and a temperature detection diode provided at a partial area defined in the array of the gate electrodes.

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.

A symmetrically-bidirectional bipolar transistor circuit where the two base contact regions are clamped, through a low-voltage diode and a resistive element, to avoid bringing either emitter junction to forward bias. This avoids bipolar gain in the off state, and thereby avoids reduction of the withstand voltage due to bipolar gain.

A semiconductor device includes a semiconductor substrate that includes a first semiconductor layer of p-type, a drift layer disposed below the first semiconductor layer, and a second semiconductor layer of n-type disposed below the drift layer. The drift layer includes a first semiconductor region of a first conductivity type, and a plurality of second semiconductor regions of a second conductivity type and a plurality of third semiconductor regions of the second conductivity type distributed in the first semiconductor region. Each of the second semiconductor regions has a shape elongated in a first direction. Each of the third semiconductor regions has a shape elongated in a second direction that is perpendicular to the first direction. The second semiconductor regions and the third semiconductor regions are alternately arranged at intervals along the first direction, and are alternately arranged at intervals along the second direction.

A semiconductor device is disclosed. In a surface layer of a front surface of an n-type semiconductor substrate, an anode layer is provided in an element activation portion and an annular p-type guard ring and an n-type high-concentration surface region are provided in an annular termination breakdown voltage region which surrounds the outer circumference of the anode layer. The impurity concentration of the n-type high-concentration surface region is higher than that of the semiconductor substrate and is lower than that of the p-type guard ring. The depth of the n-type high-concentration surface region is less than that of the guard ring. The anode layer and the guard ring are formed while the oxygen concentration of the semiconductor substrate is set to be equal to or more than 110.sup.16/cm.sup.3 and equal to or less than 110.sup.18/cm.sup.3.