| 摘要 |
PURPOSE:To make it possible to reduce to zero a breakdown current and to make possible the abrupt improvement of a static breakdown strength by a method wherein the constitution of the transistor to be used as a transistor for protecting the static electricity of power terminals is made in a constitution, wherein am impurity concentration which is higher compared to that of transistors constituting an internal circuit is provided for the impurity concentration of a substrate in the vicinity of a drain. CONSTITUTION:In a transistor Q6, a high-concentration region 26 is provided in the vicinity of the surface of a substrate 24 by such a method as an ion- implantation method and (NA' and NA are respectively the impurity concentrations of the substrate 24 and the region 26 and NA' > NA) the substrate concentration in the vicinity of a drain 22 is made higher than that in the conventional case. The transistor of such a structure is used only for protecting power terminals and the structure of transistors in other internal circuit is constituted in a structure like the conventional one. Thereby, the drain breakdown strength of the transistor Q6 is made lower than those of the transistors (Q1, Q3 and so on) in the internal circuit of 1. |
