| 摘要 |
PURPOSE:To avoid the influence of a parasitic effect upon other elements by a method wherein an optional current is applied to an isolation region corresponding to the transition of the potential of an active element from the substrate potential to a lower potential. CONSTITUTION:When a transistor Tr1 is provided as an active element, together with an epitaxial layer 2 as 1st conductive region, an epitaxial layer 8 is formed between the transistor Tr1 and the forming region of the other element as 2nd conductive region with the same conductivity type. An opposite conductivity type isolation region 4 is provided around the epitaxial layer 2 for isolation. when the potential of the epitaxial layer 2 becomes lower than the potential of a substrate 6, in accordance with the detection of the potential Vn by a potential detector 22, a current I is applied to the isolation region 4 surrounding the transistor TR1 corresponding to the generation of a negative potential. Therefore, a voltage drop is induced with the potential at the point Q of the current application as a peak so that the area required for providing the epitaxial layer 8 is reduced to a partial area where the influence upon an adjacent transistor Tr2 can be avoided. Therefore, a parasitic effect is intensified locally and the influence upon the other parts can be suppressed. |
