| 摘要 |
<p>PURPOSE:To assure a capacitor having accurate capacitance and high withstand voltage in a simplified process by implanting a first polysilicon film as a gate electrode of a MOS transistor and a second polysilicon film as a upper electrode of a capacitor simultaneously with an impurity ion. CONSTITUTION:A gate oxide film is formed, and a first polysilicon film 4 is formed by evaporation and oxidized in a clean atmosphere to form an oxide film 8. The oxide film 8 is implanted with a P31 ion. Then, a second polysilicon film 5 is formed on the oxide film 8 by evaporation and patterned to permit the size of the area thereof to be accurately defined. After the patterning, an impurity such as POCl3 is diffused at a high concentration simultaneously into the polysilicon film 4 and the second polysilicon film 5. Further, the polysilicon film 4 is patterned.</p> |
