A semiconductor device of the embodiment includes a semiconductor layer including a first semiconductor region, a second semiconductor region, a third semiconductor region, a fourth semiconductor region, a fifth semiconductor region, a sixth semiconductor region, a first trench, and a second trench, a first gate electrode in the first trench; a second gate electrode in the second trench; a first electrode on a first face side; a second electrode on a second face side; a first electrode pad connected to the first gate electrode; and a second electrode pad connected to the second gate electrode. The semiconductor device includes a first region including the first semiconductor region; a second region including the second semiconductor region; and a third region provided between the first region and the second region, the third region having a density of the second trench higher than that of the first region.

An inverter logic circuit includes a bipolar junction transistor and a zener diode. The zener diode is connected between the base of the bipolar junction transistor and ground (or other reference voltage). The zener diode is reverse biased such that a leakage current through the zener diode allows for sufficient current through the emitter-base terminals of the bipolar junction transistor when a voltage is applied across the emitter and base terminals of the bipolar junction transistor to turn the transistor ON in the absence of an external signal to the base. As such the bipolar junction transistor functions as a normally ON bipolar junction transistor.

Provided is a semiconductor device including a semiconductor substrate provided with a transistor portion, wherein the semiconductor substrate includes, in the transistor portion, a drift region of a first conductivity type; an accumulation region of the first conductivity type that has a higher doping concentration than the drift region; a collector region of a second conductivity type; and a plurality of gate trench portions and a plurality of dummy trench portions that are provided extending in a predetermined extension direction in the top surface of the semiconductor substrate, and are arranged in an arrangement direction orthogonal to the extension direction, and the transistor portion includes a first region that includes a gate trench portion; and a second region in which the number of dummy trench portions arranged in a unit length in the arrangement direction is greater than in the first region.

A semiconductor device includes a semiconductor substrate, an emitter region, a base region and multiple accumulation areas, and an upper accumulation area in the multiple accumulation areas is in direct contact with a gate trench section and a dummy trench section, in an arrangement direction that is orthogonal to a depth direction and an extending direction, a lower accumulation area furthest from the upper surface of the semiconductor substrate in the multiple accumulation areas has: a gate vicinity area closer to the gate trench section than the dummy trench section in the arrangement direction; and a dummy vicinity area closer to the dummy trench section than the gate trench section in the arrangement direction, and having a doping concentration of the first conductivity type lower than that of the gate vicinity area.

In a semiconductor device, a boundary area is between an IGBT region and a diode region. In other words, the boundary region is at a position adjacent to the diode region. The boundary region has a lower ratio of formation of a high-concentration P-type layer than the IGBT region. Accordingly, during recovery, hole injection from the IGBT region to the diode region can be inhibited. The reduced ratio of formation of the high-concentration P-type layer in the boundary region also reduces the amount of hole injection from the high-concentration P-type layer of the boundary region. Thus, it inhibits an increase in maximum reverse current during the recovery, and also decreases the carrier density on the cathode side to inhibit an increase in tail electrical current, so that the semiconductor device reduces switching loss and is highly resistant to recovery destruction.

A semiconductor device includes a first transistor and a second transistor. The first transistor includes a first body layer and a first connection part. The second transistor includes a second body layer and a second connection part. A second impedance, which is, in a path between the second connection part and the second body layer, inclusive, a maximum impedance seen by the first source electrode in the second body layer, is greater than a first impedance, which is, in a path between the first connection part and the first body layer, inclusive, a maximum impedance seen by the first source electrode in the first body layer.

A semiconductor device including a semiconductor substrate, a transistor section provided on the substrate, and a diode section provided on the substrate, the diode and transistor sections arranged in a predetermined arrangement direction, is provided. The diode section includes a first conductivity-type drift region provided in the substrate; a second conductivity-type base region in contact with an upper surface of the substrate and provided above the drift region; first cathode regions of a first conductivity-type separated from each other and second cathode regions separated from each other and having a conductivity type different from that of the first cathode regions, the first and second cathode regions being in contact with a lower surface of the substrate and provided below the drift region; and second conductivity-type floating regions separated from each other and distributed to all the first cathode regions, and arranged to at least partially overlap the first cathode regions.

A diode and a transistor are connected in parallel. The transistor is located on a first doped region forming a PN junction of the diode with a second doped region located under the first region. The circuit functions as an ionizing radiation detection cell by generating a current through the PN junction which changes by a voltage generated across the transistor. This change in voltage is compared to a threshold to detect the ionizing radiation.

A semiconductor device includes a first transistor and a second transistor. The first transistor includes a first body layer and a first connection part. The second transistor includes a second body layer and a second connection part. A second impedance, which is, in a path between the second connection part and the second body layer, inclusive, a maximum impedance seen by the first source electrode in the second body layer, is greater than a first impedance, which is, in a path between the first connection part and the first body layer, inclusive, a maximum impedance seen by the first source electrode in the first body layer.

An inverter logic circuit includes a bipolar junction transistor and a zener diode. The zener diode is connected between the base of the bipolar junction transistor and ground (or other reference voltage). The zener diode is reverse biased such that a leakage current through the zener diode allows for sufficient current through the emitter-base terminals of the bipolar junction transistor when a voltage is applied across the emitter and base terminals of the bipolar junction transistor to turn the transistor ON in the absence of an external signal to the base. As such the bipolar junction transistor functions as a normally ON bipolar junction transistor.