摘要 |
A punch-through type IGBT generally has a thick p<SUP>++</SUP>-type collector layer. Therefore, the FWD need be externally attached to the IGBT when the IGBT is used as a switching element in an inverter circuit for driving a motor load, and thus the number of processes and components increases. In the invention, trenches are formed penetrating through a collector layer and reaching a buffer layer. A collector electrode is formed in the trenches, too. With this structure, a current path is formed between an emitter electrode and the collector electrode without through the collector layer and functions as the FWD.
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