| 摘要 |
PURPOSE:To improve degree of integration and electrical reliability by electrically connecting the drain region of a MISFET and an external terminal through a semiconductor region which is of the same conductivity type as the drain region and has greater resistivity than that of the drain region. CONSTITUTION:An external input terminal (bonding pad) BP and the input stage circuit I of an internal circuit are electrically connected through an electro static breakdown prevention circuit II. In the electrostatic breakdown prevention circuit II, a protective resistance element R1 is made of a wall region 2 and has smaller resistivity than that of, e.g., a polycrystalline silicon film which is made by the same manufacturing process as semiconductor regions 7A to 7C or a gate electrode 6 so the occupying area of the protective resistance element R1 can be reduced. By electrically connecting a conductive layer 11 and the well region 2 through the semiconductor region 7C, generation of heat at the connection by excessive voltage can also be reduced so the destruction, etc., of the protective resistance element R1 can be prevented and the electrical reliability against electrostatic breakdown can be improved. |
