| 摘要 |
PURPOSE:To allow a capacitor to retain a specified quantity of capacity in the presence of an enhanced degree of device integration by a method wherein an SiO2 film is formed on an Si3N4 film, a three-layer first gate insulating film is formed, and then a first gate electrode is selectively formed. CONSTITUTION:An SiO2 film 3 that is the first insulating film, an Si3N4 film 4 that is the second insulating film, and a CVD-SiO2 film 5 that is the third insulating film are formed. Next, oxygen ions 100 are so implanted into the Si3N4 film 4 that there will be a peak concentration near the surface of the Si3N4 film 4. After the removal of the CVD-SiO2 film 5, heat treatment is accomplished in an inert gas atmosphere for the formation of a uniform and very thin oxide film 6 on the Si3N4 film 4 and, after the construction of a three-layer first gate insulating film, a first gate electrode (capacitor electrode) is built. In this way, an Si3N4 film quite high in permittivity may be employed easily. This methods allows a capacitor to retain a specified quantity of capacity even in the presence of an enhanced degree of device integration. |
