| 摘要 |
PURPOSE:To prevent the malfunction due to alpha-rays by a device wherein a collector layer and a substrate is separated from each other by a P layer and/or an insulative material, in an N-P-N bi-polar transistor using an N type Si substrate. CONSTITUTION:An N<+> buried layer 3 and a P type intermediate layer are selectively diffused into an N type Si substrate 1 by turns. Next, N epitaxial layers 4 are formed and separated by P<+> layers 2 and then connecting layers 8 ae formed for P base 6, N emitter 7 and N collector 5. The substrate 1 is given with the minimum potential. When alpha-rays enter into this structure, VCI is induced between the collector and the intermediate layer and VIS is induced between the intermediate layer and the substrate, so that the potential fluctuation at the collector is represented by VCS=VCI+VIS. Here since VCI and VIS have opposite signs, VCS=0 is obtained when concentration of each layer and a width of the intermediate layer (capacity between the intermediate and the substrate) are properly selected and their absolute values are made equal to each other. Therefore, it becomes possible to completely eliminate of fairly reduce the fluctuation in the collector potential, and particularly malfunctions of the bi-polar memory IC can be reduced or prevented. |
