| 摘要 |
To enable driving at a high withstand voltage and a large current, increase latchup immunity, and reduce ON resistance per unit area in an IGBT, a trench constituted by an upper stage trench and a lower stage trench is formed over an entire wafer surface between an n+ emitter region and a p+ collector region, and the trench is filled with a trench-filling insulating film. Thus, a drift region for supporting the withstand voltage is folded in the depth direction of the wafer, thereby lengthening the effective drift length. An emitter-side field plate is buried in the trench-filling insulating film to block a lateral electric field generated on the emitter side of the trench-filling insulating film, and as a result, an electric field generated at a PN junction between an n- drift region and a p base region is reduced.
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