| 摘要 |
A power device integrated structure comprises a semiconductor substrate (5) of a first conductivity type, a semiconductor layer (3,4) of a second conductivity type superimposed over said substrate (5), a plurality of first doped regions (2) of the first conductivity type formed in the semiconductor layer (3,4), and a respective plurality of second doped regions (11) of the second conductivity type formed inside the first doped regions (2); the power device comprises: a power MOSFET (M) having a first electrode region represented by the second doped regions (11) and a second electrode region represented by the semiconductor layer (3,4); a first bipolar junction transistor (T2) having an emitter, a base and a collector respectively represented by the substrate (5), the semiconductor layer (3,4) and the first doped regions (2); and a second bipolar junction transistor (T1) having an emitter, a base and a collector respectively represented by the second doped regions (11), the first doped regions (2) and the semiconductor layer (3,4); the doping profiles of the semiconductor substrate (5), the semiconductor layer (3,4), the first doped regions (2) and the second doped regions (11) are such that the first and second bipolar junction transistors (T2,T1) have respective first and second common base current gains sufficiently high to cause said bipolar junction transistors to be biased in the high injection region, so that carriers are injected from the substrate (5) into the semiconductor layer (3,4) and from the second doped regions (11), through the first doped regions (2), into the semiconductor layer (3,4), the conductivity of the semiconductor layer (3,4) is thus modulated not only by the injection of minority carriers from the substrate (5), but also by majority carriers injected from the doped regions (11) into the first doped regions (2) and collected by the semiconductor layer (3,4). The first and second common base current gains summed are less than unity to prevent a parasitic thyristor from triggering on. The power device functions as an IGBT, having a reduced on-state voltage. <MATH> |
