| 摘要 |
PURPOSE:To prevent the shortcircuiting between a bonding pad and a substrate by laminating two layers which have same and reverse conduction type refering to the substrate on a semiconductor substrate which lies beneath a bonding pad. CONSTITUTION:On a surface of an N-type semiconductor substrate 4 which lies beneath a bonding pad 1 an N-type semiconductor layer 6 is provided to have a wider contacting area than one which a pad 1 have to an insulation oxide film 3 that is contacted, and a P-type semiconductor layer 5 is provided so as to wrap this layer 6. Assume that the substrate 4 is biased to have the highest potential. When the oxide film 3 have a defect and shortcircuiting between the pad 1 and the layer 6 takes place, forward biased condition is held and equivalent shortcircuiting condition is resulted, but reverse biased condition is given referring to the substrate 4, and shortcircuiting between the pad 1 and the substrate 4 is prevented if an operating voltage is taken to be lower than a breakdown voltage. And when the substrate is biased to have a lowest potential, reverse biased condition is maintained between the layer 6 and the layer 5, and shortcircuiting is prevented. |
