Abstract: A semiconductor device is discloses that includes an n-type semiconductor substrate; an alternating conductivity type layer on semiconductor substrate, the alternating conductivity type layer including n-type drift regions and p-type partition regions arranged alternately; p-type channel regions on the alternating conductivity type layer; and trenches formed from the surfaces of the p-type channel regions down to respective n-type drift regions. The bottom of each trench is over the pn-junction between the p-type partition region and the n-type drift region. The semiconductor device facilitates preventing the on-resistance from increasing, obtaining a higher breakdown voltage, and reducing the variations caused in the characteristics thereof.

Abstract: An IGBT having a trench gate structure is disclosed which generates decreased noise at switching and displays superiority in saturation voltage to turn-off loss characteristics (trade-off characteristics). In a part of a region on an emitter side surface interposed between trench gates, a sub well region is provided, which is connected to an emitter electrode through diodes. When the IGBT is in a turned-on state, the diodes are brought into a non-conduction state to isolate the sub well region from the emitter electrode, by which carriers are accumulated. When the IGBT is in a turned-off state, the diodes are brought into a conduction state to electrically connect the sub well region to the emitter electrode, by which carriers are discharged at a high speed. In an early stage of turning-on of the IGBT, capacitance of a portion of the gate facing the sub well region is converted to gate-emitter capacitance to thereby reduce gate-collector capacitance, by which electromagnetic noise at switching is reduced.

Abstract: A semiconductor system includes a self arc-extinguishing device, and an IGBT that works as a thyristor when a current between a first terminal and a second terminal connected to a second well electrode is small, and as a bipolar transistor when that current is large, and automatically switches between them according to the magnitude of the current. The IGBT is formed with a first conductivity-type semiconductor substrate. On a surface layer of the substrate is a second conductivity-type well region to which a first well electrode is connected. A first conductivity-type emitter region, to which an emitter electrode is connected, is disposed on a surface layer in the well region. A control electrode is disposed through an insulating film partially covering the well and emitter regions. A second conductivity-type well layer, to which the second well electrode is connected, is disposed on a back surface side of the substrate.

Abstract: An IGBT having a trench gate structure is disclosed which generates decreased noise at switching and displays superiority in saturation voltage to turn-off loss characteristics (trade-off characteristics). In a part of a region on an emitter side surface interposed between trench gates, a sub well region is provided, which is connected to an emitter electrode through diodes. When the IGBT is in a turned-on state, the diodes are brought into a non-conduction state to isolate the sub well region from the emitter electrode, by which carriers are accumulated. When the IGBT is in a turned-off state, the diodes are brought into a conduction state to electrically connect the sub well region to the emitter electrode, by which carriers are discharged at a high speed. In an early stage of turning-on of the IGBT, capacitance of a portion of the gate facing the sub well region is converted to gate-emitter capacitance to thereby reduce gate-collector capacitance, by which electromagnetic noise at switching is reduced.

Abstract: A trench-type IGBT is disclosed that facilitates reducing the tradeoff relation between the saturation voltage and the turn-off loss.