| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that, in an IGBT or the like including an N type buffer region of a higher density than an N- type drift region in contact with a P type collector region on the rear side, a device configuration method is known which improves a switching speed by making a defect caused by an ion implantation or the like for introduction of the P type collector region or the N type buffer region residual in the N- type drift region in the vicinity of the N type buffer region but in such a structure, there is the risk of a side effect that a leak current may be increased by bringing a depletion layer into contact with a crystal defect during an OFF time.SOLUTION: In the IGBT including the N type buffer region which is provided in contact with the P type collector region at the rear side and of which the density is higher than that of the N- type drift region and a defect residual region provided in the vicinity of a boundary between the N type buffer region and the N- type drift region, in the N- type drift region closer to a front side than the defect residual region, an N type field stop region of a higher density than the N- type drift region is provided. |
