| 摘要 |
PURPOSE:To decrease to one time of an ion-implantation process and to simplify the production process of a semiconductor device by a method wherein the impurity concentration of diffused regions to be formed within an element forming region is controlled using a poly Si film formed on the sidewalls of a gate electrode. CONSTITUTION:A gate electrode 4 consisting of a poly Si film, which is selectively formed on a gate insulating film 3 within an element forming region and has a film thickness of 0.4 mum, is provided and an Si oxide film 5 of a film thickness of 200 Angstrom is formed. Then, a poly Si film 6 is deposited on the whole surface in a thickness of 0.15 mum, the film 6 is removed by an anisotropic dry etching method in such a way as to be left on parts only of the sidewalls of the electrode 4 and the etching is controlled in such a way that the height of the film 6 left on the sidewalls of the electrode 4 becomes 0.1 mum lower than that of the electrode 4. Then, phosphorus is ion-implanted at an accelerating energy of -90 keV and in a dose of 5X10<15>cm<-2> using the electrode 4 and a field insulating film 2 as masks. n<-> diffused regions 7, wherein the low-concentration photophorus is introduced, are formed within the element forming region under the lower parts of the film 6 and n<+> diffused regions 8, wherein the high-concentration phosphorus is introduced, are respectively formed within the element forming region under parts other than the lower parts of the film 6.
|
