| 摘要 |
PURPOSE:To inhibit fluctuations in characteristics by causing a gate electrode to be double layers in construction having a stepped part and also to be used as a mask and performing an ion implantation continuously toward the above gate electrode so that an energy for the ion implantation of first impurities is larger than that of second impurities. CONSTITUTION:Electical materials; insulated film 14, high conductive electrode material 15 as well as high fusing point electrode material 16 are formed in sequence on the main surface of semiconductor substrate 11 which is divided into two parts; active region 13 and element separation region 13a. A dry etching process is applied to a double layers film comprising the high fusing point electrode material 16 and high conductive electrode material 15 to form a high fusing point metal gate electrode 16a as well as high conductive gate electrode 15a respectively, resulting in the formation of a gate electrode 17 having a stepped part and then, an insulated film is shaped as a pattern to form a gate insulated film 14a. Subsequently, a different conductivity type low density region 18 consisting of N<-> region and a different conductivity type high density region 19 consisting of N<+> region are formed by performing continuously ion implantations as well as heat treatment for the gate electrode 17 and causing the gate electrode 17 to be used as a mask so that an energy for ion implantation of first impurities is larger than that of second impurities. This approach helps inhibit fluctuations in characteristics.
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