| 摘要 |
PURPOSE:To obtain excellent dielectric withstand voltage by a method wherein a polycrystalline Si film is formed on an Si nitride film, a thin polycrystalline Si containing impurities is provided thereon, a heat treatment is performed on the above, and an insulating film is formed. CONSTITUTION:An insulating film is formed on a semiconductor substrate 11 using an oxide film 12 and a nitride film 13. Then, a polycrystalline Si is grown on the film 13, a photoetching is performed thereon, and a cell plate 14 is formed. Subsequently, a thin polycrystalline Si film 24 is regrown on the cell plate 14, and phosphorus is diffused thereon, thereby enabling to give conductive property on the above films. Then, the film 24 on the part B which does not constitute a memory cell is completely converted to an oxide film 25, and this semiconductor device is oxidized by heat so that the insulating film 15 located on the plate 14 will be brought to the desired thickness. As a result, an insulating film of uniform thickness can be formed, and the semiconductor device of excellent dielectric withstand voltage can also be obtained. |
