| 摘要 |
PURPOSE:To prevent deterioration in breakdown strength and to stabilize the surrounding part of a chip, by providing a high concentration for an epitaxial layer, arranging a ring shaped diffused layer, which has the same polarity as that of a base, around a base diffused layer, and providing Al electrodes and a diffused layer, which has the same polarity as that of an emitter, around the ring shaped diffused layer. CONSTITUTION:An epitaxial layer 1, which has the same polarity as that of an Si wafer 4, is grown on the Si wafer 4. At this time, the impurity concentration of the layer 1 is controlled at the order of 10<15>cm<-3>. Then, a base layer 2 and a guard ring layer 8 are formed. Thereafter, an emitter layer and an equipotential ring shaped diffused layer 9, which has the same polarity as that of the layer 3, are formed. Finally, Al electrodes 5 for the emitter and a base and an Al electrode for the layer 9 are formed, and then an Ni electrode 6 for a collector is formed. As a result, deterioration in breakdown strength can be prevented by the layer 8 even if the concentration of the layer 1 is made high. The surrounding part of a chip, which becomes unstable after dicing, is stabilized with the Al electrodes by the layer 9. Thus, the driving current of a transistor can be decreased. |
