摘要 |
A transistor contains a first semiconductor layer of a first conductivity type and a drift layer having a pillar structure in which a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type are alternately disposed in a direction parallel to a surface of the first semiconductor layer. The fourth semiconductor layer of the first conductivity type and the fifth semiconductor layer of the second conductivity type are alternately disposed and parallel to the drift layer. The fifth semiconductor layer has a larger amount of impurities than the fourth semiconductor layer. The sixth semiconductor layer of the first conductivity type and the seventh semiconductor layer of the second conductivity type are alternately disposed and parallel to the fourth and the fifth semiconductor layers. The seventh semiconductor layer has a smaller amount of impurities than the sixth semiconductor layer.
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