| 摘要 |
PURPOSE:To enable the positioning of a gate electrode to be performed through a self-alignment manner when it is formed by a method wherein impurity diffusion for controlling the threshold voltage of a first gate electrode is made using a second gate electrode forming resist mask after the formation of the second gate electrode. CONSTITUTION:A first gate oxide film 2 and a first polycrystalline silicon film 3 are formed being laminated on a primary face of a semiconductor substrate 1, then a resist mask 4 is formed, and a first gate electrode 3 is built through etching. Next, an impurity diffused layer 6 for controlling the second gate electrode threshold voltage is formed using the first gate electrode 3 and a resist mask 5 as a mask. A process follows, where a second gate oxide film 7 and a second polycrystalline silicon film 8 are formed, then etching is performed using a resist mask 9 for the formation of a second gate electrode 8. Furthermore, an impurity diffused layer 11 for controlling the first gate electrode threshold voltage is formed on the semiconductor substrate 1 using resist masks 9 and 10 through an ion-implantation technique. |
