| 摘要 |
PURPOSE:To increase the dv/dt strength and reduce the gate ignition current by forming an island-form region similar to an emitter region on the under-side of a gate electrode at a distance farther from the emitter region. CONSTITUTION:Separately from the N<+> emitter layer 4, the N<+> island-form region 9 is provided under the gate electrode 5 in L form beneath its side opposed to the emitter layer 4 and the opposite side. Since this region 9 is in the state of being short-circuited by the gate electrode, injection due to gate forward bias does not generate in the neighborhood of the region 9, and the gate ignition current concentrates toward the A region farthest from a cathode short part 7 as shown by arrows 10. As a result, gate ignition can be produced by a small gate current independently of the dv/dt strength. The intensity of this gate ignition current is exclusively determined by the degree of restriction of flow direction, according to the opening degree of the region 9. |
