| 摘要 |
PURPOSE:To secure the thickness of an insulating films at parts of both side walls, by forming an inter-layer insulating film, which is to be formed on the first conducting pattern at the parts of both side walls of the first conducting pattern, on which an oxide film is hard to form because of the structure, with impurity concentration being made large beforehand. CONSTITUTION:On a surface 10a of a semiconductor base 10, an oxide film 11, which is to become a gate insulating film, a polysilicon 12 and an oxide film 13 are deposited. Then, the patterning of a gate electrode 14 and a wiring pattern is performed. Thereafter, an oxide film 13a is etched. Then, arsenic As 15 is applied in the polysilicon 12 and annealing is performed. Thus impurities 16 are diffused in an exposed part 12a and a part 12b, which is close to the exposed part. Thereafter, with the oixde film 13b as a mask, the polysilicon 12a is etched, and the oxide film 13b is also removed. Thus the gate electrode 14 is formed on the oxide film 11 on the semiconductor base 10. The concentration of the impurities in the gate electrode 14 is higher at both side wall parts 14b and 14c in comparison with a central part 14a. Therefore, oxidizing rate at both side wall parts is large. Dry oxidation of the electrode gate 14 is performed at the next process. An oxide film 17 can be grown at an approximately equal thickness on the flat surface and both side surfaces of the gate electrode 14. |
