| 摘要 |
PURPOSE:To enhance an insulating property of an oxide film by a method wherein, when a silicon film having the oxide film on the surface and doped with an impurity is to be formed on an insulating film, an undoped silicon film in an amorphous state is formed on the insulating film, the oxide film is formed on the surface of the silicon film by thermal oxidation and, after that, the film is doped with the impurity by ion implantation. CONSTITUTION:A field insulating film 2 and a gate insulating film 3 are formed on a silicon wafer 1 of a semiconductor device; in addition, a silicon film 6, of a prescribed thickness, in an undoped and amorphous state is formed on the insulating film 2. Then, the silicon film 6 is patterned; the surface of the silicon film 6 is thermally oxidized; an oxide film 7 corresponding to an oxide film 5 is formed. Then, ions of phosphorus are implanted from the upper part of the oxide film 7 in order to execute an activation operation; the silicon film 6 is transformed into a phosphorusdoped silicon film 8. An insulating property of the oxide film 7 is enhanced; an irregularity in its thickness is reduced. |
