| 摘要 |
PURPOSE:To increase the capacity of a capacitor by mixing impurities in an SiO2 insulation film constituting the capacitor and thereby raising specific inductive capacity in the case when MOSFET and the MOS diode type capacitor are formed integrally into IC on the same semiconductor substrate. CONSTITUTION:A thick field oxidized film 7 is formed around the Si substrate 6 and a thin gate SiO2 film 10a is connected to the surface of the substrate 6 surrounded by the film 7. In this constitution, boron ions 18 as impurities are struck into the film 10a after it is formed and thereby the specific inductive capacity of the film 10a is increased. That is, B2H6 of 1-10% is added to O2 ambience when the film 10a is formed. After that, the 1st polycrystalline Si electrode which is to be the capacitor 2 is formed and further the 2nd polycrystalline Si substrate 4 is provided with a part thereof overlapping on the former, through the intermediary of an oxidized insulation film 10b. Then, an opening is made in the film 10a contacting with the substrate 4 and an N<+> type region 5 to form a bit line is formed diffusely. |
