| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device having high field decay resistance.SOLUTION: In a voltage withstanding structure, a field limiting ring 31 is provided in a surface layer of an ndrift layer 1, and an nstopper region 32 is provided in a surface layer of the ndrift layer 1 in an outer peripheral end of a chip. A stopper electrode 34 in contact with the nstopper region 32 extends from the nstopper region 32 to a surface of an oxide film 8. The voltage withstanding structure has an ncollector layer 13 right below the nstopper region 32. With this structure, a reverse conducting diode is formed in the outer peripheral end of the chip. No pn junction is formed in the outer peripheral end of the chip, and therefore no breakdown occurs in the outer peripheral end of the chip and it is possible to substantially reduce, as compared to conventional semiconductor devices, loss (overall loss) due to IGBT operation when a field decay surge is applied. As a result, the field decay resistance of IGBT can be improved. |
