| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a conventional n-type semiconductor layer serving as a drift layer of a diode is not reduced in forward voltage VF so much since the n-type semiconductor layer is designed to be low in impurity density or large in thickness to secure a predetermined breakdown voltage, and has high resistance. SOLUTION: A diode is provided with a first p-type semiconductor region 31 on an n-type semiconductor layer surface in an operation region, and then provided with a plurality of second p-type pillar-shaped semiconductor regions 32 penetrating the first p-type semiconductor region to reach an n-type semiconductor layer at intervals of a predetermined distance. Further, a plurality of third p-type pillar-shaped semiconductor regions 33 are provided even in a terminal region at an outer periphery of the operation region at intervals of the predetermined distance. The operation region and terminal region are in a super-junction structure, so the n-type semiconductor layer is reduced in resistance by reduction in its thickness or improvement in impurity density while securing the predetermined breakdown voltage, so the forward voltage VF is lowered. COPYRIGHT: (C)2009,JPO&INPIT
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