| 摘要 |
PURPOSE:To prevent the short-circuit between an external terminal and a semiconductor substrate in case a crack is generated in the terminal by a method wherein a semiconductor region, which has the same potential as that of the terminal and has a conductivity type opposite to that of the substrate, is provided at the main surface part of the substrate under the lower part of the terminal. CONSTITUTION:An n<-> well region 11 having a conductivity type opposite to that of a p-type semiconductor substrate 10 is constituted in the main surface part of the substrate 10 under the lower part of an external terminal BP. This region 11 is constituted integrally with a well region 11 connected to a protective resistance element R of an electrostatic breakdown preventing circuit II and is consequently constituted in such a way that the region is applied in the same potential as that of the terminal BP. Moreover, the region 11 is constituted in a deep p-n junction depth, a low-impurity concentration and a large parasitic capacity, can blunt an excessive voltage sufficiently and at the same time, has a high breakdown strength of a p-n junction. Accordingly, even though a crack to reach from the terminal BP to the region 11 is generated, the short-circuit between the terminal BP and the substrate 10 is prevented because the terminal BP And the substrate 10 can be isolated electrically from each other at the p-n junction part between the region 11 and the substrate 10. |
