| 摘要 |
PURPOSE:To reduce the occupying rate of an area, by using a high resistance well as a resistor for an input protecting circuit, which is incorporated in a device, taking out wirings from the two places on the surface of the well through the same type low resistance semiconductor layers, connecting one layer to the side of an external input terminal, and connecting the other layer to the side of a circuit to be protected. CONSTITUTION:A P<-> type well 12 is selectively diffused and formed on the surface part of an N-type silicon semiconductor substrate 11. The well 12 is ohmic-contacted with wirings 13a and 13b to an external input terminal and a circuit to be protected through P<+> type semiconductor layers 14a and 14b from the two places of the surface. A signal, which is inputted to the external input terminal I, is transmitted to the wiring 13b through the wiring 13a, the low resistance P<+> type semiconductor layer 14a, the high resistance P<-> type well 12 and again the low resistance P<-> type semiconductor layer 14b. Thus the sufficient resistance value can be obtained owing to the small occupying ratio of the area.
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