| 摘要 |
PURPOSE:To obtain a triple diffusion type transistor, collector saturation voltage thereof is reduced, by forming a second base region in a first collector region and making the concentration of the second base region higher than that of a first base region and the junction of the second base region shallower than that of the first base region. CONSTITUTION:An N type impurity is implanted from a P type substrate 1 to shape an N type buried layer 2. P<+> type buried layers 3, 3' are formed similarly. An N type epitaxial layer 4 is grown, and a P type impurity is implanted to form a P type first collector region 5. A P<+> type impurity is diffused to shape P<+> type second collector regions 6 and P<+> type insulating isolation regions 6'. An N type first base region 7 is formed, and an N<+> type impurity is diffused into the region 7 to shape N<+> type second base regions 8. The P<+> type impurity is diffused so as to be in contact with the insides of the regions 8 to form a P<+> type emitter region 9. P<+> type collector contact regions 9' are shaped simultaneously at that time. Next, an N<+> type base contact region 10 is formed. |
